Surface treatments for dessicant media in a water recovery device

ABSTRACT

A system and method recover water from an ambient airstream. Dehumidification of the airstream is also achieved by removal of the water. A device of the system includes a chamber having a group of trays that hold respective amounts of liquid desiccant in each tray. A foam media absorbs the desiccant to increase an exposed surface of the desiccant to the airstream. Fans and valves are used to control airflow through the device. A charge cycle circulates air through the device to remove water vapor from the airstream. A subsequent extraction cycle removes water collected in the liquid desiccant by a condenser communicating with the chamber. An integral heat exchanger adds heat to the chamber during the extraction cycle. A controller is used to integrate and manage all system functions and input variables to achieve a high efficiency of operational energy use for water collection.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefits of and priority, under 35U.S.C. §119(e), to U.S. Provisional Application Ser. No. 61/655,316,filed Jun. 4, 2012, entitled “WATER RECOVERY SYSTEM AND METHOD,” hereinincorporated by reference in its entirety for all purposes.

FIELD OF THE INVENTION

The invention relates to a water recovery system and method ofrecovering water from ambient air. More particularly, the inventionrelates to an apparatus/device and method using a desiccant solution toextract water from the air, and then separating the water from thedesiccant. The recovered water may be treated to obtain potable water. Abyproduct of the system and method is a stream of dehumidified air thatmay be used for conditioning an interior airspace within a man-madestructure.

BACKGROUND OF THE INVENTION

Potable water is often difficult to obtain in many locations throughoutthe world. In arid climates, there is simply a shortage of water and ifwater is available, it may be difficult to make the water potablewithout extensive water treatment resources. Even in wet climates,potable water may be in short supply because of the lack of treatmentequipment. Unfortunate events such as war or general political conflictwithin a country often results in diminished infrastructure that wouldnormally have the capability to provide potable water.

There are a number of known solutions for obtaining potable water byremoving water vapor from the ambient air. One known method includespassing an airstream over a cool surface to condense the water vapor.This technique is well known, for example, in heating, ventilating, andair conditioning units (HVAC). In these types of systems, the condensedwater however is usually considered as waste material, and is disposedof.

The use of solid and liquid desiccants is also known for extractingwater from air. In a closed loop process, ambient air is passed througha chamber containing a desiccant soaked media. As the air passes incontact with the media, moisture from the air stream is removed byabsorption into the desiccant. Heat is then applied to the desiccantmedia to vaporize the captured moisture. The water vapor is transportedaway from the chamber, and then condensed and collected. The desiccantis therefore re-concentrated and can be reused in a next water recoveryeffort.

Water recovery systems include the use of both solid and liquiddesiccants. In liquid desiccant systems, one goal is to increase theexposed surface area of the desiccants to the air stream in order tomaximize water vapor removal. One method of achieving this is to spraythe liquid desiccant in a mist onto the media. However, a misting deviceadds to the complexity and cost of the system. Systems with solid formsof desiccants may provide a more compact construction. However, soliddesiccants have relatively small exposed surface areas thereby limitingthe capability to remove water vapor from a passing air stream.

One example of a reference that discloses the use of a liquid desiccantfor recovering water from an airstream is the U.S. Patent ApplicationPublication No. 2011/0232485. The reference provides a compositedesiccant material formed by a porous polyvinyl alcohol (PVA) foam ornon-woven sheets of fiber soaked in a solution of a hygroscopicdesiccant such as calcium chloride (CaCl). The desiccant is held inpores of the fiber material ranging in size from 50 microns to 1000microns. The fiber material is provided in sheets arranged in a stack ina multi-chamber system. During an absorption phase, atmospheric orambient air flows through the chamber. The water vapor is removedthrough contact with the desiccant, and is held in the fiber material.In a water recovery phase, energy is added to the chamber in the form ofheat in order to release the water from the desiccant by evaporation.Fans circulate air through the chamber, and eventually into a waterrecovery chamber within a condensing area. Water is recovered in thecondensing area, and the dried or water lean airstream leaving thechamber may be used to condition a man-made structure. As also set forthin this reference, a control system can be used to operate fans withinthe water recovery system when conditions of humidity and the remainingcapacity of the desiccant stack are conducive to an efficient chargingoperation to remove water from the ambient air. The control system mayalso initiate a regeneration cycle when the availability of low gradeheat energy and the degree of saturation of the desiccant are conduciveto removing water from the desiccant, that is, when the degree ofmoisture in the chamber is high enough relative to the temperature of anavailable cold source for an efficient condensing operation. U.S. PatentApplication Publication No. 2011/0232485 is herein incorporated byreference in its entirety for all purposes.

Another example of a patent reference that discloses a method and devicefor recovering water from ambient air is the U.S. Pat. No. 6,156,102.Specifically, this reference discloses separating water from air by theuse of a liquid desiccant to withdraw water from air, treatment of theliquid desiccant to produce water, and regenerating the desiccant forsubsequent use. In one preferred embodiment, the method disclosedincludes providing a hygroscopic solution comprising a solute in aninitial concentration; contacting the hygroscopic solution with ambientair containing water to obtain a water rich hygroscopic solution havinga concentration of solute less than the initial concentration and awater lean airstream; separating the water lean airstream from the waterrich hygroscopic solution; releasing the water lean airstream to theatmosphere; and treating the water rich hygroscopic solution to obtainwater and to return the hygroscopic solution to its original state forre-use. U.S. Pat. No. 6,156,102 is herein incorporated by reference inits entirety for all purposes.

As described in the U.S. Pat. No. 6,156,102, the effectiveness of liquiddesiccants can be expressed in terms of both their “drying efficiency”and “drying capacity”. Drying efficiency is the ratio of total waterexposed to the hygroscopic solution as compared to the amount of waterremoved. The drying capacity is the quantity of water that a unit massof desiccant can extract from the air. The drying efficiency and dryingcapacity of a hygroscopic solution is in part dependent upon thepressure of the water vapor in the air and on the concentration of thesolute. In general, a hygroscopic solution having a high concentrationof solute and thus a low partial pressure of water vapor in the solute,more quickly absorbs water from air having a higher partial pressure ofwater vapor. Accordingly, the hygroscopic solution has an initial dryingefficiency that is relatively high. As water continues to be absorbedduring a water recovery process, the partial pressure of the water vaporin the solution increases and the rate of water absorption slows down.Eventually, the hygroscopic solution and the air may reach equilibrium,and no more water will be absorbed by the hygroscopic solution. In adesiccant regenerative process for the hygroscopic solution, thecollected water in the hygroscopic solution must be removed. U.S. Pat.No. 6,156,102 is herein incorporated by reference in its entirety forall purposes.

While the prior art may be adequate for its intended purposes, there isstill a need for a water recovery system and method that takes advantageof a modular construction in order to provide an integral capability tocontrol parameters for efficient recovery of water from an ambientairstream. There is also a need to provide a construction that is easilyadaptable to maximize water recovery for a specific application orsituation. There is also a need to provide a water recovery system andmethod in which pre-established logic can be used to control the waterrecovery device based upon known environmental factors and taking intoconsideration the necessary amount of water to be produced. There is yetfurther a need to provide a device and method that requires a minimumamount of energy for operation, and is conducive to accepting forms ofwaste heat for operation. There is also a need to provide a waterrecovery device and method that is reliable, simple to operate, andrequires minimum intervention for daily operations. There is also a needto provide a water recovery device and method that is easy to transport,deploy and commission. There is also a need to provide a water recoverydevice in which monitoring of the concentration of the liquid desiccantsolution is achieved automatically, in order to timely and efficientlyrecover water once the liquid desiccant solution has reached its watersaturation limit. During the regenerative phase of a desiccant solution,it is preferable that the concentration of the desiccant does not becometoo high, which otherwise could result in crystallization orsolidification of the liquid desiccant resulting in a reduced efficiencyof the device until the desiccant chemical can be placed back into itsoptimal concentration with water.

SUMMARY OF THE INVENTION

The present invention includes a system and method for recovering waterfrom an ambient airstream. Additionally, the invention achievesdehumidification of the airstream by removal of the water. The device ischaracterized by a group or stack of trays that hold an amount of liquiddesiccant in each tray. A foam media absorbs or wicks the desiccant toincrease the exposed surface area between the desiccant and theairstream that is passed through an enclosed chamber that holds thedesiccant trays. A number of fans and dampers or valves are used tocontrol the airflow through the chamber.

Operation of the device includes two cycles. The first cycle is a chargecycle in which ambient air is passed through the chamber, across thedesiccant stack, and back to the environment. The desiccant causes watervapor in the airstream to be taken up and held in a foam media materialthat holds the desiccant. In a preferred embodiment, the desiccant is aliquid solution of CaCl and water that is impregnated into the foammedia. The foam media may include a thin sheet of PVA that is arrangedin an accordion folded manner to increase the surface area of the sheetthat is exposed to the airstream. Once the desiccant media has absorbeda sufficient amount of water from the airstream, an extraction cycle isinitiated to recover water from the desiccant solution. In this cycle,the chamber is isolated from the ambient air, and energy is added to thechamber in order to vaporize the water from the desiccant solution. Inaddition to heat energy, the interior pressure of the chamber may bereduced to lower the evaporation temperature required to vaporize thewater. For example, a fan can be used to remove an amount of air withinthe chamber, and then the chamber can be sealed to maintain the lowerpressure state. One or more fans circulate the air within the chamberacross the desiccant media to increase the rate of evaporation. When theinternal temperature of the chamber exceeds a dew point temperature,relative to the external ambient conditions, a condensing circuit isenabled to condense the water vapor from the internal chamber air. Theextraction cycle may also be referred to as a regeneration cycle inwhich the removal of water from the desiccant solution regenerates thedesiccant placing it in a condition for re-use in which theconcentration of the desiccant is returned to an optimal percentage.

Heat energy may be added to the chamber through a water or glycol-basedheat exchanger. There are several possible sources of heat energy thatcan be used to include solar collectors, photovoltaic cells, waste heatfrom nearby industrial sources, electrical heaters, and gas heaters,among others.

The condensed water is captured, and may be further treated in order tomake potable water. For example, the recovered water may be filtered,exposed to an ultra violet light source, mineralized, chlorinated, ormay be otherwise treated to make the water safe for consumption.

A controller is used to integrate and manage all system functions andinput variables to achieve a high efficiency of operational energy usefor water output. The controller uses sensor inputs to estimate theamount of water in the system, the power used, the power stored, and therelevant external and internal environmental conditions such astemperature, pressure, humidity, sunlight/darkness. During theextraction cycle the controller is used to control heat energy added tothe chamber and to also control the condensing rate to therefore sustaincontinuous operation for recovering water from a previous charge cycle.The controller may take advantage of sensor inputs and software thatincorporates a number of algorithms to maximize efficiency of operation.For example, the algorithms may synthesize these inputs to control heatenergy added to the chamber in a manner that minimizes energy usage fromheat delivery systems and from fans and other internal components.During the charging cycle, similar inputs and algorithms can be used tocontrol power consumption of fans and other internal components and toensure a maximum water uptake.

For both system cycles, the algorithms may define optimal operatingconditions for a known geographical area and a known calendar date whichcomprises historical data regarding average temperature, humidity, andsunlight/darkness conditions. From these algorithms, a baselineoperating sequence can be established, and then modified by actualenvironmental conditions at the time. The controller receives multipleinputs that measure temperature, humidity, and pressure of the deviceduring operation. Consequently, the controller manipulates outputs toefficiently operate the device by controlling outputs such as fans,dampers, and heat energy added to the device. During an extraction orregeneration cycle, the controller monitors the amount of water removedfrom the chamber to ensure that too much water is not removed that couldresult in a high desiccant concentration and crystallization of thedesiccant.

In another aspect of control, the invention may include a system inwhich one or more devices may communicate with remote computing deviceswithin a communications network. These remote computing devices can beused to assist in control of the device(s) and to gather data from thedevices or to send updated commands for device operation. Accordinglyeach controller may further include a wireless transmission andreceiving capability. In this regard, a system of the invention maytherefore also include multiple devices, each of the devices having awireless communication capability.

In another aspect of control, the invention may include “location based”capabilities in which Global Positioning System (GPS), magnetometer orother location based sub-systems are used to identify location andorientation of the installed system. This information can be used tofurther exploit data about geographical and/or weather conditions toenable better system efficiencies. For example, knowledge of orientationand duration of sunlight, directions of prevailing winds, etc may beused to obtain better efficiencies for solar energy extraction andminimized fan power needs, respectively.

In another feature of the invention, the device has a modularconstruction in which the desiccant trays can be arranged in a desiredconfiguration. Further, the modular construction takes advantage ofuniform sized tubing and couplers/flanges that allow for easy assemblyand disassembly of the device. Further, the fans and dampers may also beof uniform construction, therefore allowing interchangeability amongcomponents, for ease of assembly/disassembly.

In yet another feature of the invention, the modular construction allowsfor a number of different options for adding heat energy to the device.Each of the desiccant trays may be configured to connect to a heatingassembly. The heating assembly, in a preferred embodiment, may include aheating coil placed in close proximity to heat distribution fins. Theheating assembly itself may be configured as a stackable tray unit.

In yet another feature of the invention, the airflow through the chamberof the device may be dynamically configured to optimize desired waterextraction. For example, each of the desiccant trays may include airflowopenings on one or more sides of the trays that control the direction ofairflow through the chamber. In one example, the airflow may take atorturous path through the chamber in which there is a single or serialpath through each of the desiccant trays.

In another example, the airflow may take a parallel flow pattern throughthe chamber in which there may be multiple paths available for airflowthrough the chamber. Accordingly, airflow through the chamber may beconfigured to best match fan capabilities in moving an optimum flow ofair through the device.

In yet another feature of the invention, the dried airstream that isproduced when leaving the device may be used for a number ofapplications, such as providing a humidity controlled airstream tocondition an airspace within a building or other man made structure.Particularly in hot, humid climates, the dried airstream produced cangreatly improve working and living conditions within habitable spaces.

Although calcium chloride is disclosed for use as a preferred chemicalhygroscopic desiccant, it should be understood that there are a numberof other hygroscopic desiccants that could be used. For example, lithiumbromide, magnesium chloride, and lithium chloride are known as effectivehygroscopic desiccants. However, one advantage of calcium chloride isthat it is a non-toxic chemical, and is therefore safe to use.

In one aspect of the invention, it can be considered a system forrecovering water from ambient air. In another aspect of the invention,it can be considered an apparatus for recovering water from ambient airwith options for manual control, automatic control, or combinationsthereof. In another aspect of the invention, it can be considered asystem for dehumidifying ambient air for purposes of providingconditioned air for an interior space of a man made structure.

In another aspect of the invention, it may include varioussub-combinations of the system and device. These sub-combinations mayinclude (1) the desiccant stack, (2) the heat exchanger with thedesiccant stack, (3) the desiccant stack and the condenser, (4) thedesiccant stack, heat exchanger, and condenser, and (5) and thedesiccant stack, heat exchanger, and condenser further in combinationwith a controller. Each of these sub-combinations has utility.

Other aspects of the invention include a construction for a desiccantcartridge, a method of selectively controlling air flow through achamber for a water recovery device, a modular construction for a waterrecovery device utilizing easily assembled components, a method forcontrolling a charging cycle of a water recovery apparatus including theuse of algorithms to optimize operation, a method for controlling anextraction cycle of a water recovery apparatus including the use ofalgorithms to optimize operation, a method of operating a water recoverydevice including the use of algorithms to minimize energy usage, amethod of operating a water recovery device including the use ofalgorithms to provide an even and continuous operation of a waterrecovery device, and a method of controlling operation of a waterrecovery device incorporating a plurality of control inputs includingvarious sensors, weigh scales, and flow meters. Yet further aspects ofthe invention include a water recovery device utilizing multiple energysources to power an extraction cycle, a method of determining optimalformulations for a liquid desiccant solution used within a waterrecovery device, a construction for a desiccant media including aformulation for a liquid desiccant solution, a water recovery deviceincluding configurable desiccant media cartridges, a method forselective and dynamic control of a liquid desiccant solution used withina water recovery device, a water recovery device including insulatingand sealing components that effectively isolate airflow through thedevice and otherwise provide optimal temperature and pressure conditionswithin a chamber of the device, and a method for determining an optimalinitial desiccant formulation of a water recovery device consideringrelevant geographical data corresponding to the geographical locationwhere the device is to be installed.

In one aspect of the invention, it can be considered a method ofrecovering water from ambient air by directing an ambient airstream to awater recovery device, which includes a desiccant stack including achamber defining an airflow path therein, the stack including aplurality of desiccant trays, each tray including a desiccant mediacartridge and an amount of liquid desiccant placed within the tray andbeing absorbed by a media material of the media cartridge; a condensercommunicating with the desiccant stack; a heat exchanger communicatingwith the desiccant stack for providing heat to the desiccant stack;wherein the water recovery device is operated in a charge cycle forcirculating ambient air through the chamber to remove water vapor by theliquid desiccant and retaining water vapor in the chamber, the devicebeing further operated in an extraction cycle to remove the retainedwater vapor within the chamber, the condenser providing a cooling sourceto condense the water vapor and thereby producing an amount of watercondensate; and collecting the water condensate.

The water recovery devices of the invention may comprise media materialsselected from a silica gel, activated charcoal, calcium sulfate, calciumchloride, montmorillonite clay, crushed aluminum, alumino silicates,sodium alumino silicates, ceramic, porous ceramic, cellular plastic,expanded metal foil, coarse fiber, felt, alumina ball, glass fiber,membrane and micro-cellulous, metal oxides, metal chlorides, metalsilanes, hydrides, calcium silicates, calcium sulfate, magnesiumsulfate, calcium chloride, calcium oxide, portland cement, perlite,vermiculite, attapulgite clay, bentonite clay, phosphorous pentoxide,aluminum phosphate, aerogel, glycerin, phosphorous pentoxide, a zeolite,zeolite A, zeolite 13X, silica gel granules coated with cobalt chloride,silica gel pellets, molecular sieves, or combinations thereof.

The water recovery devices of the invention may also comprise a liquiddesiccant selected from ionic compounds comprising an anion selectedfrom acetate, fluoride, chloride, thiocyanate, dicyanamide, chlorate,perchlorate, nitrite, nitrate, sulfate, hydrogensulfate, carbonate,hydrogencarbonate, methylcarbonate, phosphate, hydrogenphosphate,dihydrogenphosphate, phosphonate HPO32-, hydrogenphosphonate H2PO3-,sulfamate H2N—SO3-, deprotonated acesulfame, deprotonated saccharine,cyclamate, tetrafluoro-borate, trifluoromethanesulfonate,methanesulfonate, nonadecafluoro-nonansulfonate and p-toluolsulfonate,methylsulfate, ethylsulfate, n-propylsulfate, i-propylsulfate,butylsulfate, pentylsulfate, hexylsulfate, heptylsulfate, octylsulfate,nonylsulfate, decylsulfate, long-chain n-alkylsulfate, benzylsulfate,trichloroacetate, dichloroacetate, chloroacetate, trifluoroacetate,difluoroacetate, fluoroacetate, methoxyacetate, cyanacetate, glykolate,benzoate, pyruvate, malonate, pivalate, the deprotonated or partiallydeprotonated form of the following monovalent or polyvalent acids:formic acid, acetic acid, propionic acid, butyric acid, valeric acid,caproic acid, enanthic acid, caprylic acid, capric acid, lauric acid,myristic acid, palmitic acid, stearic acid, arachidic acid,O-acetylsalicylic acid, sorbic acid, pivalic acid, fatty acids,isoleucine, alanine, leucine, asparagine, lysine, aspartic acid,methionine, cysteine, phenylalanine, glutamic acid, threonine,glutamine, tryptophan, glycine, valine, proline, serine, tyrosine,arginine, histidine, ornithine, taurine, sulfamic acid, aldonic acids,ulosonic acids, uronic acids, aldaric acids, gluconic acid, glucuronicacid, mannonic acid, mannuronic acid, galactonic acid, galacturonicacid, ascorbic acid, glyceric acid, xylonic acid, neuraminic acid,iduronic acid, oxalic acid, malonic acid, succinic acid, glutaric acid,adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid,phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaricacid, glutaconic acid, traumatic acid, muconic acid, citric acid,isocitric acid, aconitic acid, propane-1,2,3-tricarboxylic acid,trimesic acid, glycolic acid, lactic acid, malic acid, citric acid,tartaric acid, mandelic acid, 2-hydroxybutyric acid, 3-hydroxybutyricacid, 4-hydroxybutyric acid, 3-hydroxypropionic acid,3-hydroxyisoyaleric acid, salicylic acid, polycarboxylic acids, PF6-,[PF3(CF3)3]-, [PF3(C2F5)3]-, [PF3(C3F7)3]-, [PF3(C4F7)3]-,[F3C—SO2-N—SO2-CF3]-, [F3C—SO2-N—CO—CF3]-, [F3C—CO—N—CO—CF3]-,dimethylphosphate, diethylphosphate, dibutylphosphate, dimethylphosphonate, diethyl phosphonate, dibutyl phosphonate, and mixturesthereof, and a cation selected from tetramethylammonium,tetraethylammonium, tetrabutylammonium tetrahexylammonium,tetraoctylammonium, trimethylammonium, triethylammonium,tributylammonium, triethylmethylammonium, tributylmethylammonium,trihexylmethylammonium, trio ctylmethylammonium,tris-(2-Hydroxyethyl)methylammonium, tris-(2-Hydroxyethyl)ethylammonium,bis-(2-hydroxyethyl)dimethylammonium, 1,3-dimethylimidazolium,1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium,1-butyl-3-methylimidazolium, 1,2,3-trimethylimidazolium,1,3-diethylimidazolium, 1,3-dibutylimidazolium,1-ethyl-2,3-dimethylimidazolium, 1-butyl-2,3-dimethylimidazolium,1-(2-hydroxyethyl)-3-methylimidazolium,1-(3-hydroxypropyl)-3-methylimidazolium,1-(2-hydroxypropyl)-3-methylimidazolium,1-(4-hydroxy-butyl)-3-methylimidazolium,1-(3-hydroxy-butyl)-3-methylimidazolium,1-(2-hydroxy-butyl)-3-methylimidazolium,1-(2-methoxyethyl)-3-methylimidazolium,1-(3-methoxypropyl)-3-methylimidazolium,1-(2-methoxypropyl)-3-methylimidazolium,1-(4-methoxy-butyl)-3-methylimidazolium,1-(3-methoxy-butyl)-3-methylimidazolium,1-(2-methoxy-butyl)-3-methylimidazolium,1-(2-ethoxyethyl)-3-methylimidazolium,1-(3-ethoxypropyl)-3-methylimidazolium,1-(2-ethoxypropyl)-3-methylimidazolium,1-(4-ethoxy-butyl)-3-methylimidazolium,1-(3-ethoxy-butyl)-3-methylimidazolium,1-(2-ethoxy-butyl)-3-methylimidazolium, 1-allyl-3-methylimidazolium,1-allyl-2,3-dimethylimidazolium, N,N-dimethylmorpholinium,N,N-diethylmorpholinium, N,N-dibutylmorpholinium,N-ethyl-N-methylmorpholinium, N-butyl-N-methylmorpholinium,N,N-dimethylpiperidinium, N,N-diethylpiperidinium,N,N-dibutylpiperidinium, N-ethyl-N-methylpiperidinium,N-butyl-N-methylpiperidinium, N,N-dimethylpyrrolidinium,N,N-diethylpyrrolidinium, N,N-dibutylpyrrolidinium,N-ethyl-N-methylpyrrolidinium, N-butyl-N-methylpyrrolidinium,2-Hydroxyethyltrimethylammonium (choline),2-acetoxyethyl-trimethylammonium (acetylcholine), guanidinium(protonated guanidine, CAS 113-00-8), tetramethylguanidinium,pentamethylguanidinium, hexamethylguanidinium triethylmethylphosphonium,tripropylmethylphosphonium, tributylmethylphosphonium,tetraethylphosphonium, tetrapropylphosphonium, tetrabutylphosphonium,tetramethylphosphonium, and mixtures thereof.

The preceding is a simplified summary of the disclosure to provide anunderstanding of some aspects of the invention. This summary is neitheran extensive nor exhaustive overview of the disclosure and its variousaspects, embodiments, and/or configurations. It is intended neither toidentify key or critical elements of the disclosure nor to delineate thescope of the disclosure but to present selected concepts of thedisclosure in a simplified form as an introduction to the more detaileddescription presented below. As will be appreciated, other aspects,embodiments, and/or configurations of the disclosure are possibleutilizing, alone or in combination, one or more of the features setforth above or described in detail below. Therefore, other features andadvantages of the present disclosure will become apparent from a reviewof the following detailed description, taken in conjunction with thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the device of the invention in onepreferred embodiment;

FIG. 2 is an exploded perspective view of a desiccant tray and desiccantmedia cartridge;

FIG. 3 is another perspective view of the desiccant tray with thedesiccant media cartridge mounted within the tray;

FIG. 4 is a vertical section of the desiccant tray of FIG. 2 showingdetails of the arrangement of the desiccant media cartridge and anamount of desiccant solution within the tray;

FIG. 5 is an exploded perspective view of a heat exchanger assembly;

FIG. 6 is a perspective of the assembled heat exchanger assembly of FIG.5;

FIG. 7 is a vertical section of a desiccant tray mounted over a heatexchanger assembly, illustrating the relationship between heatdistribution elements of the heat exchanger and the desiccant tray;

FIG. 8 is a fragmentary perspective of the device in a preferredembodiment;

FIG. 9 is a perspective view of a preferred embodiment of a desiccantstack including a plurality of vertically stacked desiccant trays, aheat exchanger assembly located beneath the desiccant trays, and a stackexhaust manifold for directing exhaust air from the desiccant stack;

FIG. 10 is a vertical section of FIG. 9 illustrating the relationshipbetween the desiccant trays and the heat exchanger assembly;

FIG. 11 is a schematic diagram of a desiccant stack, and oneconfiguration for an airflow path through the chamber, referred toherein as a parallel flow path;

FIG. 12 is another schematic diagram of a desiccant stack, and anotherconfiguration for an airflow path through the chamber, referred toherein as a serial flow path;

FIG. 13 is an exploded perspective of components of the device includinga fan and damper/valve combination;

FIG. 14 is an assembled perspective of the components of FIG. 13;

FIG. 15 is a schematic diagram of components of a controller that may beused in conjunction with control of the device; and

FIG. 16 is a schematic diagram of a communication system, including aplurality of devices with integral controllers operating within acommunications network in which one or all of the devices maycommunicate with other communication nodes of the network, to includedownload and upload of data and commands.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1, a schematic diagram is shown for purposes ofillustrating the major functional components of a device of the system.Specifically, the device 10 includes a housing 12 that defines thereinan interior space or chamber for receiving a flow of air to remove watervapor from the airstream. The chamber is more specifically defined asincluding a desiccant stack 14 including a plurality of desiccant trays74 (see FIG. 2) that each holds a desiccant media material.

Each of the trays 74 have a quantity of a liquid desiccant solutionplaced in contact with the desiccant media material that wicks orabsorbs the solution, as set forth further below with respect to thedescription of the FIGS. 2-4. The device 10 further includes one or moreheat exchanger assemblies 16 for providing heat to the chamber. A weighscale 18 is used to monitor the mass of water vapor that is collectedfrom the airstream during a charge cycle, as well as the mass of watervapor that is removed from the liquid desiccant solution during anextraction cycle.

An ambient or environmental or ambient air intake line 20 provides anentry point for the ambient air to enter the chamber area. The ambientair entering the chamber follows a flow path 22 through the heatexchanger assembly 16 and the desiccant stack 14. In the schematicdiagram of FIG. 1, the flow path 22 illustrates a winding or torturouspath, which is explained in more detail below with respect toconfigurable flow paths shown in the FIGS. 11 and 12. An exhaust line 24returns the airstream that has traveled through the chamber back to theatmosphere. Alternatively, the exhaust line 24 may communicate withductwork of a man made structure (not shown) to provide a conditionedairstream for the structure.

The airstream through the chamber may take one of several paths,depending upon the particular cycle in which the device is operating atthe time. In the case of a charge cycle, the airstream is exhausted tothe atmosphere or manmade structure through the exhaust line 24. Duringan extraction cycle, air within the chamber exits the chamber throughthe condenser inlet line 26 that interconnects the chamber with thecondenser 28. Also during an extraction cycle, prior to when air withinthe chamber reaches the desired saturated state ready for condensing,air is re-circulated through the chamber by re-circulating line 72, asalso discussed below.

FIG. 1 also schematically illustrates a cooling coil 30 that is used tocondense the moist airstream for extraction of water vapor from theairstream. An ambient air cooling line 32 is also illustrated within thecondenser 28. During the extraction cycle, ambient air is used as thecooling source for condensing the warmer, moist airstream that hasentered the cooling coil 30. A water collection container 34 is providedfor collecting the condensed water by water line 36 that interconnectsthe condenser 28 to the container 34. A weigh scale 38 may also be usedto monitor the amount of water extracted. In conjunction with scale 18,the scale 38 provides control inputs for monitoring water recovery.

The heat exchanger assembly 16 includes a heat source 40. The heatsource 40 in the schematic of FIG. 1 is shown as a solar collector orphotovoltaic cell; however the heat source could be many other sourcessuch as an electric or gas heater, or available waste heat sources. Forexample, the heat source could include waste heat from an industrialprocess, or waste heat captured from the exhaust manifold or engine of avehicle. A closed loop heating line 44 is used to re-circulate an amountof heating fluid. As shown, the heating line 44 traverses through thechamber and in close proximity with the desiccant stack 14. The heatingfluid 42 may be a conventional heating fluid such as water or glycol. Aheating fluid container 45 is provided to store the heating fluid. Afluid pump 70 is used to re-circulate the heating fluid 42 through theheating line 44. Although FIG. 1 illustrates the heat source 40 andcontainer 45 as separated from the other components of the heatexchanger assembly 16 within the chamber, it shall be understood thatthe heat exchanger assembly 16 could be housed in a number of differentconfigurations to accommodate the particular application which thedevice is being used.

A controller 84 may be used to provide automatic control of theoperation of the device. The controller 84 may take the form of knownindustrial controllers that accommodate control inputs and outputs, anda processor with integral software or firmware. With respect to inputs,the device may be monitored by a number of temperature sensing devices46, such as thermocouples or RTDs. In FIG. 1, there are a number oftemperature sensors shown at various locations throughout the device.Within the heat exchanger assembly, a number of temperature sensingdevices 46 are also shown to include sensors located within the heatexchanger, and within the heating line at the entrance and exit from theheat source 40. A number of temperature sensors are also illustratedwithin the desiccant stack 14, as well as within the condenser 28.

In addition to temperature control, the FIG. 1 also illustrates a liquidflow sensor 48 that measures the flow rate of the heating fluid 42through the heating line 44. An airflow sensor 49 may also beincorporated within the exhaust line 24 to monitor the flow rate of airthrough the chamber. Further, a number of relative humidity sensors 50may be incorporated within the device to measure relative humidity ofthe airstream. As shown in FIG. 1, relative humidity sensors 50 may beco-located with temperature sensors 46 at the exhaust line 24, at thecondenser return line 73, and at other selected locations in which itmay be desirable to monitor the relative humidity.

With respect to controlling airflow through the device, a number of fansmay be used to precisely control airflow. Referring again to the FIG. 1,the fans may include an intake fan 52 communicating with the air intakeline 20, an exhaust fan 56 that communicates with the exhaust line 24, acondenser fan 68 that introduces air into the condenser 28 alongcondenser inlet line 26, a re-circulating fan 64 that re-circulates airthrough the chamber through re-circulating line 72, and an ambient aircooling fan 69 that introduces ambient air into the condenser 28.Control of air flow through the device is also achieved through a numberof dampers or valves. Again referring to the FIG. 1, the group of valvesmay include an air intake valve 54 mounted in the air intake line 20, anexhaust valve 58 that is mounted in the air exhaust line 24, a condenserinlet valve 62 that is mounted in the condenser inlet line 26, and are-circulating valve 66 that is mounted in the condenser return line 73.

Referring now to FIGS. 2-4, a desiccant tray 74 is illustrated inaccordance with a preferred embodiment. The tray 74 includes sidewalls90, and a base 96. One or more of the sidewalls 90 may include rodreceiving channels 94 that receive rods or dowels (not shown) thatstabilize the connection between stacked trays 74. At least one pair ofopposing sidewalls 90 may include an interior flange 92 for mounting asealing gasket 75 (see FIG. 8). Preferably, there is a sealing gasketplaced between each stacked tray 74 to thereby limit airflow lossthrough the chamber. The base 96 holds an amount of liquid desiccantsolution 110 (FIG. 4). The base 96 includes base sidewalls 98, and oneor more of the sidewalls 98 may include a plurality of airflowcirculation slots or openings 100. As shown, these openings 100 aredisposed at the upper portion of base sidewalls 98, above the liquidline 112 of the liquid desiccant solution 110, and below the top edge ofthe sidewalls 90. FIGS. 2-4 also illustrate a desiccant media cartridge82 that is placed within the desiccant tray 74, as best illustrated inthe FIG. 3. The media cartridge 82 is shown as a rectangular shapedelement that fits within the confines of base sidewalls 98. The mediacartridge 82 includes a media frame 102 that holds media material 120 inan accordion folded configuration. The media frame 102 may also includeone or more frame panels 104 that can be used to direct airflow throughthe chamber by preventing air from passing through the panels 104. Inthe FIG. 2, it is intended to show that the two end walls of the mediaframe 102 include media frame panels 104, while the opposing sidewallsof the media frame 102 remains open thereby allowing airflowhorizontally through the media cartridge 82. In order to stabilize theopen sides of the frame 102, the frame may further include screensupports 106 comprising a plurality of wire elements as shown.

Referring to FIG. 4, the media material 120 is illustrated in the formof a thin sheet that is held in the accordion folded configuration tothereby maximize the exposed surface area of the media material to airpassing through the chamber. As shown, the desiccant solution 110 fillsa portion of the base 96, and the lower end of the media material 120 issubmerged in the fluid solution 110. As mentioned, one example of anacceptable media material may include a thin sheet of PVA foam, anabsorbent foam that readily wicks the desiccant solution 110. The terms“PVA”, “PVA wicking media”, and “wicking media” refer to an element thatis configured to wick desiccant solution. In order to maintain the mediamaterial in the accordion folded configuration with uniform gaps orspaces between the folds of material, an internal wire support 122 maybe used for stabilizing the media material. When the media material 120absorbs or wicks the desiccant solution 110, the material serves toevenly distribute the desiccant solution in large surface area within aconfined space. Accordingly, the media material 120 and the desiccantsolution 110 provide a hygroscopic feature to effectively remove watervapor from a passing airstream. As shown in the FIG. 4, the mediamaterial 120 is preferably oriented in a parallel relationship with theflow of air, thereby enabling air to pass through the gaps between thefolds of the media material. In this orientation, the airstreammaintains significant contact with the exposed surfaces of the mediamaterial. As air continues to flow through a media cartridge 82, theamount of water vapor retained in the media material increases. It ispossible for the amount of retained water vapor to exceed the liquidholding capacity of the media material, resulting in dripping of thedesiccant solution into the pool of desiccant fluid 110. As discussedfurther below, it is advantageous to begin an extraction cycle prior tocomplete saturation of the media material.

The thickness of the media material, as well as the configuration of themedia material in terms of the size of the gaps between folds of themedia material can be adjusted to meet the desired water recovery needsfor a particular use. Thinner sheets of material with larger gapsbetween folds of the material allows for better airflow through thechamber, thereby reducing the airflow pressure drop through the chamber.However, this configuration of the media material limits the amount ofwater vapor that can be removed from the airflow. Reducing the size ofthe gaps between the folds of the media material and increasing thewidth of the media material results in increased capability to removewater from the airflow, but with the disadvantage of increased pressuredrop through the chamber therefore requiring greater fan capacity inmoving air through the chamber. It is therefore contemplated to adjustthe particular configuration of the media material so that waterrecovery is achieved to meet the needs of the particular use of thedevice without excessive air pressure drop through the device that mayexceed the capacity of the fans.

As shown in FIG. 4, the media material 120 is configured in an accordionfolded configuration in which the individual folded sections present asubstantially linear cross-sectional profile to the airflow, namely astraight line profile except for the upper and lower curved transitionsections to the adjacent folded section. The accordion folded (orpleated) configuration of the media material 120 allows for unobstructedair flow and channels the air in the desired direction with minimalresistance. The vertically-arranged accordion folded configuration alsoreduces system sensitivity to leveling and presents a reduced footprintcompared to conventional media material configurations that orient themedia material in a horizontal arrangement. More specifically, the waterrecovery system of the present invention is more adapted to resistmisalignment between adjacent sections of media material, in contrast totraditional, horizontally-mounted media material which are extremelysusceptible to system horizontal misalignment due to the shrinkage ofthe media material and the natural misalignment that occurs as the mediamaterial is also deformed in shape due to its dual role as a structuralsupport element. Also because of the horizontal alignment of mediamaterial in many prior art devices, this alignment contributes tonon-uniform drying of media material and thus non-uniform and typicallyinefficient airflows. Further, because the majority of the desiccant inthe present invention is stored in a tray, a relatively smaller hardwarefootprint may be presented when compared to conventional desiccant mediadesigns.

There are a number of distinct advantages with respect to the particulardesign of the desiccant trays and media cartridges. The majority of thedesiccant (both in a wet and dry state) is stored mostly in the traywhile a smaller percentage is stored in the PVA media foam. In prior artdevices, the method of storing the desiccant is typically achieved bysolely confining the desiccant to the wicking media. Accordingly, thepresent invention has a much higher capacity to store water.Additionally, the PVA foam, or similar wicking media, has severaladvantageous functions. For example, the PVA serves as a transportchannel for water contained in the air path, and also as a storagemedium for saturated desiccant. As further described herein, the PVAwicking media enhances surface area for the passing airflow, andtherefore serves to increase evaporation and absorption kinetics.Further, an over-saturation of the desiccant will not impair performanceof the system because the media will not leak out of the device, butrather an equilibrium amount of desiccant will remain. That is, in manywater recovery systems, over-saturated media and their containmentapparatus have no means to dispose or contain excess moisture, thusleading to inevitable leakage. Further, the inability to dispose orcontain excess moisture in these prior art devices can also result inuncontrolled vapor pressure increases that can further contribute toundesirable leakage. In contrast, the water recovery system of thepresent invention is designed to accept and direct excess moisture andmaintain a balanced amount of desiccant. Because of the ability to keepthe desiccant at equilibrium, the operating range of the systemincreases to higher humidity levels with little to no reduction in lowerhumidity performance. Also, the performance of the system will improveover time, in contrast to traditional water recovery systems usingpre-charged saturated desiccant elements which degrade with eachextraction cycle.

The PVA foam, or similar wicking media as configured in the presentinvention, is resistant to over-drying and does not serve as astructural element. Typically, PVA foam shrinks when dried. In manyprior art water extraction systems, the PVA foam is not supported andtherefore must serve also as a structural element. Also, the PVA foam istypically mounted in a horizontal fashion, and perpendicular to the flowof air. As such, when the PVA foam becomes dried (such as might occurwhen the system is run under dry conditions with little humidity), thePVA shrinks, folds/curls and may become brittle, causing obstructions tothe airflow, compromising structural integrity and reducing systemefficiencies. In contrast, the system of the present invention isresistant to over-drying of PVA foam because the PVA foam is used withina cartridge support element that has provides structural support to thePVA foam. Therefore, the PVA foam is isolated from contact with externalstresses and strains, and is able to maintain its shape throughoutcontinuous use. Also, the vertically-mounted configuration of the PVAfoam as described herein reduces airflow disruption upon PVA shrinkage,because should a given PVA element curl in one air channel, the secondside of the PVA element exposes double the area so the net airflow willnot be impeded.

As used herein, the term “desiccant” and “drying agent” are usedinterchangeably and are meant to refer to any material capable of takingup free water and holding it. The term “absorb” and variants thereof,are not meant to indicate any specific mechanism of free water take-up,attraction or capture, for example whether through adsorption orabsorption, and are meant to be inclusive of each, and any variantthereof. All that is meant by “absorb” herein is that water is taken up(attracted or captured) by the desiccant or drying agent in a mannerthat results in a enhancement to set up or cure of the coating, film,membrane or barrier.

The media material may be composed of a desiccant material to enhancethe removal of water from the airflow. Alternatively, the media materialmay be coated with a desiccant. Alternatively, the media material may beboth composed of and coated with a desiccant. In these embodiments, thecoating may be uniformly applied to the media material or may be appliedto partially cover the surface(s) of the media material. In certainembodiments, the coating may be strategically applied to areas of themedia material to maximize the water retained by the media material orminimize the coating in areas of low water retention.

The desiccant may retain water through either a chemical reaction tocapture the water, such as the conversion of CaO to its hydrated form,or through adsorption of water to a high surface area lattice, such asin the SiO/AlO lattice of zeolites. The advantage of the latter is thatthey can be regenerated after saturation at relative low temperatures(<300° C.), easing the processing constraints.

Thus water retention performance depends, at least in part, on totalsurface area and pore volume. The desiccant may therefore be preparedas, or applied to, a high surface honeycomb-like matrix.

The media material may comprise materials such as a silica gel,activated charcoal, calcium sulfate, calcium chloride, montmorilloniteclay, crushed aluminum, alumino silicates, sodium alumino silicates,ceramic, porous ceramic, cellular plastic, expanded metal foil, coarsefiber, felt, alumina ball, glass fiber, membrane and micro-cellulous,metal oxides (such as of calcium or magnesium), metal chlorides (such aschlorides of calcium or magnesium), metal silanes (such astetraethoxysilane or vinyl silanes), hydrides (such as calcium hydrideand lithium hydride), calcium silicates, calcium sulfate, magnesiumsulfate, calcium chloride, calcium oxide, portland cement; perlite;vermiculite; attapulgite clay(s); bentonite clay(s); phosphorouspentoxide; aluminum phosphate, aerogel(s); glycerin, phosphorouspentoxide, zeolite A, zeolite 13X, silica gel granules coated withcobalt chloride, silica gel pellets, and/or molecular sieves. Amolecular sieve is a material containing tiny pores of a precise anduniform size that is used as an adsorbent for gases and liquids.Molecules small enough to pass through the pores are adsorbed whilelarger molecules are not. It is different from a common filter in thatit operates on a molecular level and traps the adsorbed substance. Forinstance, a water molecule may be small enough to pass through the poreswhile larger molecules are not, so water is forced into the pores whichact as a trap for the penetrating water molecules, which are retainedwithin the pores. Because of this, they often function as a desiccant. Amolecular sieve can adsorb water up to 22% of its own weight. Theprinciple of adsorption to molecular sieve particles is somewhat similarto that of size exclusion chromatography, except that without a changingsolution composition, the adsorbed product remains trapped because inthe absence of other molecules able to penetrate the pore and fill thespace, a vacuum would be created by desorption. Often they consist ofaluminosilicate minerals, clays, porous glasses, microporous charcoals,zeolites, active carbons, or synthetic compounds that have openstructures through which small molecules, such as nitrogen and water candiffuse. Molecular sieves are often utilized in the petroleum industry,especially for the purification of gas streams and in the chemistrylaboratory for separating compounds and drying reaction startingmaterials. For example, in the liquid natural gas (LNG) industry, thewater content of the gas needs to be reduced to very low values (lessthan 1 ppmv) to prevent it from freezing (and causing blockages) in thecold section of LNG plants. Methods for regeneration of molecular sievesinclude pressure change (as in oxygen concentrators), heating andpurging with a carrier gas (as when used in ethanol dehydration), orheating under high vacuum. Temperatures typically used to regeneratewater-adsorbed molecular sieves range from 130° C. to 250° C.

Zeolites are microporous, aluminosilicate minerals commonly used ascommercial adsorbents. The zeolite family (Nickel-Strunz classification)includes:

09.GA—Zeolites with T5O10 units—the fibrous zeolites

Edingtonite, gonnardite, kalborsite, mesolite, natrolite, paranatrolite,scolecite, thomsonite

09.GB—Chains of single connected 4-membered rings

Analcime, leucite, pollucite, wairakite, laumontite, yugawaralite,goosecreekite, montesommaite

09.GC—Chains of doubly-connected 4-membered rings

Amicite, boggsite, garronite, gismondine, gobbinsite, harmotome,phillipsite, merlinoite, mazzite, paulingite, perlialite

09.GD—Chains of 6-membered rings—tabular zeolites

Bellbergite, bikitaite, erionite, faujasite, ferrierite, gmelinite,offretite, willhendersonite, chabazite, levyne, maricopaite, mordenite,dachiardite, epistilbite

09.GE—Chains of T10O20 tetrahedra

Barrerite, brewsterite, clinoptilolite, heulandite, stilbite

Others

Cowlesite, herschelite, pentasil (also known as ZSM-5), sodiumdachiardite, stellerite, tetranatrolite, tschernichite, wellsite.

Portland cement primarily comprises calcium silicates; i.e. CaOSiO2, forexample 3CaOSiO2 and 2CaOSiO2. The ratio of CaO to SiO2 is typically notless than 2.0. Other materials are typically present, in minor amounts,for example calcium sulfate and magnesium oxide.

CaCl2 and silica gels may be used as composite desiccants. In addition,zeolite 13X and CaCl2 may be used as composite desiccants. Thesedesiccants may be prepared as composite adsorbent materials byimpregnating the micropores/mesopores of silica activated carbon with aninorganic salt, such as CaCl2. CaCl2 can adsorb approximately 0.9 g ofwater vapor per gram of CaCl2 at room temperature and pressure.Additional composites utilizing CaCl2 may include CaCl2 and expandedgraphite, or activated carbon impregnated with CaCl2. Similarly lithiumsalts, such as LiBr and LiCl, and CaCl2 contained within a corrugated orextended surface substrate may be used.

As solid materials making up the media material and/or coating the mediamaterial, the desiccant(s) may be in the form of finely dividedparticles, preferably with a median particle size of less than 20 μm,more preferably less than 10 μm and especially less than 5 μm.

In addition to the use of desiccant materials composing the mediamaterial or coated on the media material or impregnated in the mediamaterial, the device of the invention may utilize liquid desiccantsolution(s) that may be in contact with the media material and may beremoved from contact with the media material during normal systemoperations.

In the instances of liquid desiccant solutions, the carrier fluid chosento carry the desiccant is typically non-aqueous, so that the ability ofthe desiccant to absorb water from the airflow is not reduced.Similarly, the carrier fluid for the desiccant composition is preferablyone that is not very hygroscopic, i.e., does not readily absorb water,so that during storage and handling water is not absorbed into thedesiccant at a rate that would undesirably effect (deactivate) thedesiccant.

Adjuvants may also be included in the desiccant solution. For example,emulsifier or dispersant, to facilitate dispersion of the desiccant ordying agent, can be used. A dispersion agent is a material that operatesto disperse the powder of the desiccant or drying agent in the liquidcomposition. It can be characterized as a surfactant, typicallyoperating as an anionic dispersant when used in typical applicationsaccording to the present disclosure. A desiccant solution can be formedby adding the dispersant (emulsifier) to the solvent, with mixing in ahigh speed disperser. Suspending agents can be included to help maintainthe desiccant in dispersion. A suspending agent is an agent or mixturethat operates as a stabilizer or thickening agent. That is, it createsan increase in viscosity or apparent viscosity, to facilitate inhibitionof settling, of the desiccant. An example of an emulsifier or dispersantis Lica 38, a organic titanate coupling agent. Examplary suspendingagents include various clays, for example, attapulgite clay(s).

The amount of desiccant included, per volume, in the desiccant solutionwill be chosen based, in part, by understanding the amount of water inthe airflow available to be absorbed or captured, and also byunderstanding the water-absorbing characteristic of the desiccant (forexample, Portland cement can absorb about five times its weight inwater). One of skill in the art can determine the amount of desiccantthat needs to be intimately dispersed in a selected volume of desiccantsolution.

The liquid desiccant that may be used in the device is preferably chosento remain in liquid form. For example, typical halide salts turn tosolid phase when the relative humidity drops below low levels and thusare generally not considered for use in liquid phase when trying toreduce the relative humidity of the airflow below 20%. Thus, thepreferred liquid desiccant may be an ionic liquid; the ionic liquids mayhave an electric multi-pole moment, such as an electric dipole momentand/or an electric quadrapole moment. The ionic liquid may be a pureionic liquid, i.e. a liquid substantially containing only anions andcations, while not containing other components, e.g. water.Alternatively, the initial ionic liquid may be a solution containing theionic liquid and a solvent or further compound, e.g. water, may be used.In the most generic form, the ionic liquids may be represented by[Q+]n[Zn−], wherein Q represents a cation and Z represents an anion.

Anions of the above ionic liquids may be selected from acetate,fluoride, chloride, thiocyanate, dicyanamide, chlorate, perchlorate,nitrite, nitrate, sulfate, hydrogensulfate, carbonate,hydrogencarbonate, methylcarbonate, phosphate, hydrogenphosphate,dihydrogenphosphate, phosphonate HPO32-, hydrogenphosphonate H2PO3-,sulfamate H2N—SO3-, deprotonated acesulfame, deprotonated saccharine,cyclamate, tetrafluoro-borate, trifluoromethanesulfonate,methanesulfonate, nonadecafluoro-nonansulfonate and p-toluolsulfonate,methylsulfate, ethylsulfate, n-propylsulfate, i-propylsulfate,butylsulfate, pentylsulfate, hexylsulfate, heptylsulfate, octylsulfate,nonylsulfate, decylsulfate, long-chain n-alkylsulfate, benzylsulfate,trichloroacetate, dichloroacetate, chloroacetate, trifluoroacetate,difluoroacetate, fluoroacetate, methoxyacetate, cyanacetate, glykolate,benzoate, pyruvate, malonate, pivalate, the deprotonated or partiallydeprotonated form of the following monovalent or polyvalent acids:formic acid, acetic acid, propionic acid, butyric acid, valeric acid,caproic acid, enanthic acid, caprylic acid, capric acid, lauric acid,myristic acid, palmitic acid, stearic acid, arachidic acid,O-acetylsalicylic acid, sorbic acid, pivalic acid, fatty acids,isoleucine, alanine, leucine, asparagine, lysine, aspartic acid,methionine, cysteine, phenylalanine, glutamic acid, threonine,glutamine, tryptophan, glycine, valine, proline, serine, tyrosine,arginine, histidine, ornithine, taurine, sulfamic acid, aldonic acids,ulosonic acids, uronic acids, aldaric acids, gluconic acid, glucuronicacid, mannonic acid, mannuronic acid, galactonic acid, galacturonicacid, ascorbic acid, glyceric acid, xylonic acid, neuraminic acid,iduronic acid, oxalic acid, malonic acid, succinic acid, glutaric acid,adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid,phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaricacid, glutaconic acid, traumatic acid, muconic acid, citric acid,isocitric acid, aconitic acid, propane-1,2,3-tricarboxylic acid,trimesic acid, glycolic acid, lactic acid, malic acid, citric acid,tartaric acid, mandelic acid, 2-hydroxybutyric acid, 3-hydroxybutyricacid, 4-hydroxybutyric acid, 3-hydroxypropionic acid,3-hydroxyisoyaleric acid, salicylic acid, polycarboxylic acids, PF₆ ⁻,[PF₃(CF₃)₃]⁻, [PF₃(C₂F₅)₃]⁻, [PF₃(C₃F₇)₃]⁻, [PF₃(C₄F₇)₃]⁻,[F₃C—SO₂—N—SO₂—CF₃]⁻, [F₃C—SO₂—N—CO—CF₃]⁻, [F₃C—CO—N—CO—CF₃]⁻,dimethylphosphate, diethylphosphate, dibutylphosphate, dimethylphosphonate, diethyl phosphonate, dibutyl phosphonate, and mixturesthereof.

Cations of the above ionic liquids may be selected fromtetramethylammonium, tetraethylammonium, tetrabutylammoniumtetrahexylammonium, tetraoctylammonium, trimethylammonium,triethylammonium, tributylammonium, triethylmethylammonium,tributylmethylammonium, trihexylmethylammonium, trio ctylmethylammonium,tris-(2-Hydroxyethyl)methylammonium, tris-(2-Hydroxyethyl)ethylammonium,bis-(2-hydroxyethyl)dimethylammonium, 1,3-dimethylimidazolium,1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium,1-butyl-3-methylimidazolium, 1,2,3-trimethylimidazolium,1,3-diethylimidazolium, 1,3-dibutylimidazolium,1-ethyl-2,3-dimethylimidazolium, 1-butyl-2,3-dimethylimidazolium,1-(2-hydroxyethyl)-3-methylimidazolium,1-(3-hydroxypropyl)-3-methylimidazolium,1-(2-hydroxypropyl)-3-methylimidazolium,1-(4-hydroxy-butyl)-3-methylimidazolium,1-(3-hydroxy-butyl)-3-methylimidazolium,1-(2-hydroxy-butyl)-3-methylimidazolium,1-(2-methoxyethyl)-3-methylimidazolium,1-(3-methoxypropyl)-3-methylimidazolium,1-(2-methoxypropyl)-3-methylimidazolium,1-(4-methoxy-butyl)-3-methylimidazolium,1-(3-methoxy-butyl)-3-methylimidazolium,1-(2-methoxy-butyl)-3-methylimidazolium,1-(2-ethoxyethyl)-3-methylimidazolium,1-(3-ethoxypropyl)-3-methylimidazolium,1-(2-ethoxypropyl)-3-methylimidazolium,1-(4-ethoxy-butyl)-3-methylimidazolium,1-(3-ethoxy-butyl)-3-methylimidazolium,1-(2-ethoxy-butyl)-3-methylimidazolium, 1-allyl-3-methylimidazolium,1-allyl-2,3-dimethylimidazolium, N,N-dimethylmorpholinium,N,N-diethylmorpholinium, N,N-dibutylmorpholinium,N-ethyl-N-methylmorpholinium, N-butyl-N-methylmorpholinium,N,N-dimethylpiperidinium, N,N-diethylpiperidinium,N,N-dibutylpiperidinium, N-ethyl-N-methylpiperidinium,N-butyl-N-methylpiperidinium, N,N-dimethylpyrrolidinium,N,N-diethylpyrrolidinium, N,N-dibutylpyrrolidinium,N-ethyl-N-methylpyrrolidinium, N-butyl-N-methylpyrrolidinium,2-Hydroxyethyltrimethylammonium (choline),2-acetoxyethyl-trimethylammonium (acetylcholine), guanidinium(protonated guanidine, CAS 113-00-8), tetramethylguanidinium,pentamethylguanidinium, hexamethylguanidinium triethylmethylphosphonium,tripropylmethylphosphonium, tributylmethylphosphonium,tetraethylphosphonium, tetrapropylphosphonium, tetrabutylphosphonium,tetramethylphosphonium, and mixtures thereof.

Strong liquid desiccant systems for use in the device include desiccantmaterials such as a CaCl₂ and water or LiCl₂ and water solution toabsorb water vapor in the airflow. After the desiccant absorbs moisturefrom the air stream, it is heated to release the excess water. Whenthese strong liquid desiccants are used, the media material may comprisetitanium, which is reasonably suitable for use with desiccants such asCaCl₂ or LiCl₂, due to the corrosive nature of the desiccants.

Additional preferred liquid desiccants include aqueous alkali halides,aqueous alkali nitrates, and/or glycol. Such alkali halides may includelithium bromide (LiBr), lithium chloride (LiCl), calcium chloride(CaCl₂), zinc chloride (ZnCl₂), zinc bromide (ZnBr) and the like. Alkalinitrates include potassium nitrate (KNO₃), and lithium nitrate (LiNO₃),and the like. Glycol includes ethylene glycol (C₂H₆O₂) and the like.Sodium silicate solutions are also useful in the liquid desiccantsystems of the device of the invention.

In the instance in which a solid media material is used, the mediamaterial may be surface treated to change the surface area of the mediamaterial to increase the absorption and/or adsorption of water on themedia material. Additionally, the surface energy of the media materialmay be adjusted in this way to maximize the adsorption of specificdesiccant species, thereby providing the maximal exposure of thedesiccant to the airflow across the media material.

Surface treatments to the media material may include passivation (forexample, chlorination or fluoridation) or activation (such as ionbombardment via wet or dry methods) physical modifications such asetching, drilling, cutting, or abrasion, and chemical modifications suchas solvent treatment, the application of primer coatings, theapplication of surfactants, plasma treatment, ionbombardment/implantation and covalent bonding. The media material may bealtered by any of the methods mentioned above to alter the retentionand/or release characteristics of the surface of the media material withrespect to the desiccant and/or water to improve the exposure of thedesiccant to the airflow through/past the media material and tomaximize, to the extent possible, the collection of water by thedesiccant and the media material.

The desiccant solution 110 is placed in each of the trays 74. This maybe done manually at the start of operation of the device. As the devicecontinues to operate, it may be necessary to replenish the desiccantsolution. For example, some portions of the desiccant media that absorbthe desiccant solution may become dried and crystallized, therebypreventing reactivation of the desiccant chemical without cleaning andre-soaking the desiccant media. In lieu of manually replacing thedesiccant solution 110, it is also contemplated that the desiccantsolution 110 may be automatically replenished. A desiccant solutionreservoir (not shown), and a water reservoir (not shown) may have fluidconveying lines that connect to each or selected ones of the trays 74.Each of the trays may also include a liquid level sensor (not shown)and/or a desiccant concentration sensor (not shown) to sense theconcentration of the chemical desiccant. Chemical concentration sensorsare devices that measure the electrical potential of a solution, andchanges in the electrical potential correspond to known changes in theconcentration of a chemical within the solution. Based on inputs fromthese sensors, replenishment valves (not shown) mounted in the fluidconveying lines could be selectively opened to release a designatedamount of water and/or desiccant solution in order to replenish thedesiccant solution in the trays. In many cases, it may only be necessaryto add water back to the desiccant solution in order to place it at theoptimum desiccant concentration.

Referring now to FIGS. 5 and 6, components are illustrated for the heatexchanger assembly 16 that reside below a desiccant stack 14. As shown,the assembly includes a housing 76, including sidewalls 130 and a bottomwall or base 128. One side of the housing 76 includes a tubing manifold132 with openings to receive corresponding tubing sections 134.Extending upward from the base 128 is a plurality of baffles 140 thatare used to support the heating distribution element 78. As shown, theheating distributional element 78 is also an accordion folded elementthat fits between the sidewalls 130, and is disposed above the heatingline 44. The heating line 44 is configured in a winding path to therebymore evenly transfer heat to the heat distribution element 78. Theheating line 44 passes through one of the sidewalls 130 as shown in FIG.6, and communicates with the heat source 40 and container 45 (FIG. 1).Optionally, a wire support element 136 maybe disposed within the housing76 in order to maintain the heating element 78 in its accordion foldedconfiguration. The heat distribution element 78 may be made fromaluminum or another type of corrosive resistant conductor. The housing76 may also include rod receiving channels 138 that align with channels98 of the desiccant trays 74 to receive stabilizing rods (not shown)that help to hold the desiccant stack and heat exchanger assembly in astabilized vertical orientation.

Referring to FIG. 7, the arrangement of a desiccant tray 74 is shownwith respect to the heat exchanger housing 76. As shown, the base orbottom portion of the desiccant tray 74 is located in close proximity tothe upper surfaces the heat distribution element 78. This orientationmay allow for most efficient heat transfer to the overlying tray 74.FIG. 7 also illustrates the available space for air entering the devicein which the air first passes through the gaps between adjacent sectionsof the heat distribution element 78. The airstream is then directedupwards, through the openings 100 in the base sidewall 98 of the tray.Next, air is forced horizontally through the gaps in the media material120 and substantially parallel with the orientation of the mediamaterial 120. The air then travels upward into the next desiccant tray74. The path of airflow through this next desiccant tray is dictated bythe orientation of the openings 100 in the base sidewalls 98 of thetray.

Referring to FIG. 8, a preferred embodiment is illustrated for thedevice 10 with respect to construction details for the desiccant stack14, heat exchanger 16, and the group air conveying elements includingfans, valves, conveying lines, and connectors. More specifically, theFIG. 8 illustrates a desiccant stack 14 arranged in a plurality ofdesiccant trays 74 stacked vertically upon one another over a singleheat exchanger assembly 16. The most upper tray 74 is removed forillustration purposes to shown a sealing gasket 75 that is placedbetween stacked trays. The stack exhaust manifold 80 is also shown inwhich airflow from the chamber is returned to the atmosphere throughlines 24. As shown in this embodiment, instead of a single exhaust line24, there is a pair of exhaust lines 24 arranged as the outside pair ofconveying lines in the group of four adjacent lines. The embodiment ofFIG. 8 is intended to illustrate that some of the conveying elements maybe provided in duplicate for better airflow control of the device.Accordingly, in addition to duplication of the exhaust lines 24 andassociated fans and valves, the FIG. 8 also illustrates duplication ofthe condenser inlet line 26, re-circulating line 72, return line 73, andthe associated valves and fans for these lines. FIG. 8 also shows anoptional fan 75 associated with each return line 73 if additional forceis required to remove the air from the condenser 28. In the event aparticular installation of the device calls for the dual lineconfiguration such as shown in this figure, it may also be advantageousto incorporate air distribution manifolds at the junctions between theselines and the condenser in order to simplify the connections between thelines and the condenser. Accordingly, the FIG. 8 also shows respectivemanifolds 81 and 83. In FIG. 8, the condenser 28 is shown in a schematicform only, and it shall be understood that the distal free ends of thelines 26 and 73 interconnect with the inlet and outlet of the condensercoil 30. If manifolds 81 and 83 are employed, these manifoldscommunicate with the inlet and outlet of the condenser coil 30,respectively. Because of the angle of view in FIG. 8, another inlet line20 and associated conveying elements cannot be seen, but the FIG. 8 isintended also to represent that there can also be duplication of theseelements. FIG. 8 does not illustrate all of the other components of thecondenser as shown in FIG. 1, but it shall also be understood that thecondenser includes these other elements. Additionally, it iscontemplated that the condenser 28 could have more than one condensercoil 30. Thus, if a dual line configuration is used such as shown inFIG. 8, it is also contemplated that each of the line pairs 26 and 73could be connected to separate coils 30.

In terms of the modular construction of the device, it is clear that thedesiccant trays 74 may be conveniently stacked on top of one another ina space saving arrangement. Additionally, the location of the variousfans and valves may be conveniently located adjacent the desiccant stackto maintain a relatively small device profile. The lines for conveyingairflow may be a plurality of uniform tubing sections, and the tubingsections may connect to one another by a friction fit. Therefore, it isunnecessary to provide sealing gaskets between each and every tubingsection. As discussed in more detail below with respect to the FIGS. 13and 14, the modular construction of the invention further allows forfriction fit attachments between the sections of tubing and the variousvalves and fans.

Referring to FIG. 9, a desiccant stack 14 is illustrated in the samearrangement as shown in the FIG. 8, but with the various tubingsections, valves, and fans removed. Referring to the FIG. 10, thisvertical cross-sectional clearly illustrates the compact and orderlyarrangement of the desiccant trays when placed in a verticalconfiguration. Although the FIGS. 9 and 10 illustrate a verticaldesiccant stack arrangement; it is also contemplated that a desiccantstack could include combinations of both vertically and horizontallyextending desiccant trays. Accordingly, with respect to a horizontallyextending group of desiccant trays, each of the desiccant trays couldalso include a tubing manifold 132 in lieu of solid sidewalls 90 and 98enabling horizontally adjacent trays 74 to communicate with one anotherby tubing sections interconnecting the trays by their correspondingmanifolds 132. Therefore, one can appreciate the highly configurablenature of the device in terms of adjusting its shape and size for aparticular use. For uses of the device with greater water recoveryrequirements, a larger number of trays can be used to increase waterrecovery, or uses of the device with lesser water recovery requirementsmay dictate a fewer number of trays be used. The requisite number of airconveying lines, fans, and valves can be added to a desiccant stack toensure proper airflow through the device for purposes of bothmaintaining airflow through the device during a charging cycle, as wellas airflow through the device during an extraction cycle.

Referring to FIGS. 11 and 12, in yet another aspect of the invention, itis contemplated that a user may dynamically configure the flow path ofair through the device in order to maximize efficiency for the intendeduse of the device. In the example of FIG. 11, a parallel flow path isillustrated by the directional arrows in which each of the trays 74 haveopposing base sidewalls 98 with openings 100, which therefore allowsairflow to travel upwards in a vertical manner through the chamber andalso horizontally through the media cartridges 82. The only blockedsidewall with no openings 100 is the solid sidewall 180 located abovethe heat exchanger assembly 16. This sidewall 180 ensures the airinitially passes through the heat exchanger for purposes of heating theair, for example, during an extraction cycle. As shown in the FIG. 11air may travel horizontally through either a first lower mediacartridge, or the media cartridge in the second or next higher tray 74.

In the example of FIG. 12, the directional arrows show a torturous orserial flow path that is provided through the chamber of the device.Accordingly, alternating and opposite sidewalls of the stacked desiccanttrays 74 include the solid sidewalls 180 without openings 100. One canappreciate the advantages of the dynamic and modular construction of thepresent invention in which the trays can be placed not only in variouscombinations of vertical and horizontal arrangements, but also each traymay be configured with either solid sidewalls 180 or sidewalls 98 withopenings 100 in order to establish a desired airflow path through thechamber, and thereby maximizing airflow for the intended use of thedevice.

Referring now to FIGS. 13 and 14, an example construction is providedfor a valve or damper and fan combination. As shown, in the schematicdiagram of FIG. 1, airflow control through the device includes variouspairs of fans and dampers. Accordingly, the FIGS. 13 and 14 are intendedto illustrate how these various pairs of fans and dampers may beconstructed in accordance with the advantages of the modularconstruction of the invention. A fan assembly 150 is shown as includinga fan housing 158 disposed between a pair of fan flanges 156. The fan160 is disposed within the fan housing 158, and includes acharacteristic fan hub, and a plurality of fan blades. A valve assembly152 connects to the fan assembly. A single connecting flange 162 may beplaced between the valve assembly and fan assembly. The construction ofthe valve assembly 152 may include two half sections, shown as upperhalf section 164 and lower half section 166. The flapper or valveelement 168 has a mounting pin 170, which is received in the pinopenings 174 of the upper half section 164. Pin locks 172 may be used tosecure the ends of the mounting pin 170. As also shown in FIG. 13, anadjacent tubing or conduit section 154 may be secured to the fan also bya single connecting flange 162. Similarly, the opposite end of the valveassembly 152 may connect to an adjacent tubing section 154 by a singleconnecting flange 162. The tubing sections 154 may simply befrictionally received within the adjacent flanges 162. The half sections164 and 166 may be secured to the flanges 164 also by a friction fit, asachieved by the flange extensions 176, or by some other connecting meansin which substantial airflow loss is limited between the connections. Asalso shown, the fan 150 may be secured to its abutting flanges 162 as bya screw and nut combination. The FIGS. 13 and 14 are intended toillustrate an example construction in which pairs of fans and valves maybe connected to one another in line with sections of tubing, wherein theconstruction is simple, reliable, and repeatable without the need forspecial tools or equipment. Thus, functionally distinct pairs of fansand valves of the device when installed in the device may be assembledby similar assembly methods.

In order to control the device, an integral controller 84 (FIG. 1) maybe used. While manual control is also possible, use of a controller hasa number of advantages to include less burdensome user efforts, and moretimely and precise control of the device for producing the desiredamount of water. The controller 84 may be a known industrial controller,such as a programmable logic controller (PLC).

Referring to the FIG. 15, this figure is intended to represent thecontroller 84 as a computing device 200 with known functionality. Morespecifically, FIG. 15 illustrates one embodiment of a computing device200 comprising hardware elements that may be electrically coupled via abus 255. The hardware elements may include one or more centralprocessing units (CPUs) 205; one or more input devices 210 (e.g., amouse, a keyboard, etc.); and one or more output devices 215 (e.g., adisplay device, a printer, etc.). The computing device 200 may alsoinclude one or more storage device 220. By way of example, storagedevice(s) 220 may be disk drives, optical storage devices, solid-statestorage device such as a random access memory (“RAM”) and/or a read-onlymemory (“ROM”), which can be programmable, flash-updateable and/or thelike. The controller 200 also includes one or more input/output modules201. The input/output modules may be built in with the controller, ormay be one or more external input/output modules that plug into thecontroller. For PLCs, most of these are equipped with extensiveinput/output module capabilities in which a wide range of inputs andoutputs may be accommodated. Further, because PLCs are typically madefor severe operating conditions, the use of a PLC as a controller in thedevice of the invention may be a preferred option.

The computing device 200 may additionally include a computer-readablestorage media reader 225; a communications system 230 (e.g., a modem, anetwork card (wireless or wired), an infra-red communication device,etc.); and working memory 240, which may include RAM and ROM devices.Optionally, the computing device 200 may include a processingacceleration unit 235, which can include a DSP, a special-purposeprocessor and/or the like. The computer-readable storage media reader225 can further be connected to a computer-readable storage medium,together (and, optionally, in combination with storage device(s) 220)comprehensively representing remote, local, fixed, and/or removablestorage devices plus storage media for temporarily and/or morepermanently containing computer-readable information. The communicationssystem 230 may permit data to be exchanged with a data network and/orwith another computing device within a network, as further explainedbelow regarding FIG. 16.

The computing device may also comprise software elements, shown aslocated within a working memory 240, including an operating system 245and/or other code 250, such as program code implementing a program orcode for operation of the device. The computing device 200 may alsoemploy a GPS receiver 260 for location based capabilities. The GPSreceiver 260 can be used to further exploit data regarding geographicaland/or weather conditions to improve the operational efficiency ofdevice. For example, the GPS receiver can be used to download dataregarding orientation and duration of sunlight and the direction(s) ofprevailing winds. This data can be used to update or improve thealgorithms to obtain better efficiencies for solar energy extraction andto minimize fan power needs. The computing device 200 may other includea radio transceiver 265 that enables the device to have a wirelesscommunications capability. A particular radio communications protocolmay be employed depending upon geographical limitations where the deviceis installed, enabling the device to maintain wireless communicationswith a wireless communications network.

Alternate components of the computing device might also be used and/orparticular elements might be implemented in hardware, software(including portable software, such as applets), or both. Further,connection to other computing devices such as network input/outputdevices may be employed.

Although the device has been described with the use of a computingdevice 200, it is also contemplated that the device may also becontrolled by one or more microcontrollers. A microcontroller is anintegrated chip including a central processing unit (CPU), a memoryelement (such as RAM or ROM), a group of input/output ports, and timers.Microcontrollers, however, are typically designed to execute only alimited number of tasks because of the limited processor capabilitiesand therefore, are limited in terms of their ability to monitor numerousinputs and to generate numerous command outputs. Nonetheless, because ofthe relatively few inputs and outputs of the device, a microcontrollerin combination with a communications element, such as a transceiver witha wireless capability, remains as a viable solution in terms ofproviding control for the device.

The computing device or microcontroller(s) may also be incorporatedwithin a communications network, as shown in the FIG. 16. The FIG. 16 isintended to illustrate that either a computing device ormicrocontroller(s) be represented by the reference numeral 200. Further,the FIG. 16 is intended to illustrate an example communication system300 that may be used in connection with the device and method disclosedherein. The system 300 may include one or more remote general purposecomputers 305 and 310 that communicate through a communications network310 with one or more of the devices 10, each with their own integralcontroller/microprocessor(s) 200. By way of example, the general purposecomputers may be personal computers and/or laptop computers runningvarious versions of Microsoft Corp.'s Windows™ and/or Apple Corp.'sMacintosh™ operating systems) and/or workstation computers running anyof a variety of commercially-available UNIX™ or UNIX-like operatingsystems. These remote computers 305 and 310, may also have any of avariety of applications, including for example, database client and/orserver applications, and web browser applications. Alternatively, theuser computers 305 and 310 may be other electronic devices, such as anInternet-enabled mobile telephone, and/or personal digital assistant,capable of communicating via the network 320 and/or displaying andnavigating web pages or other types of electronic documents. Althoughthe exemplary system 300 is shown with two remote computers, any numberof remote computers may be supported.

The network 320 may be any type of network familiar to those skilled inthe art that can support data communications using any of a variety ofcommercially-available protocols, including without limitation TCP/IP,SNA, IPX, AppleTalk, and the like. Merely by way of example, the network320 maybe a local area network (“LAN”), such as an Ethernet network, aToken-Ring network and/or the like; a wide-area network; a virtualnetwork, including without limitation a virtual private network (“VPN”);the Internet; an intranet; an extranet; a public switched telephonenetwork (“PSTN”); an infra-red network; a wireless network (e.g., anetwork operating under any of the IEEE 802.11 suite of protocols, theBluetooth™ protocol known in the art, and/or any other wirelessprotocol); and/or any combination of these and/or other networks.

The system 300 may also include one or more server computers 325. Theserver 325 may be a web server, which may be used to process requestsfor web pages or other electronic documents from user computers 305 and310. The web server can be running an operating system including any ofthose discussed above, as well as any commercially-available serveroperating systems. The web server 325 can also run a variety of serverapplications, including HTTP servers, FTP servers, CGI servers, databaseservers, Java servers, and the like. In some instances, the web server325 may publish operations available as one or more web services.

The system 300 may also include a database 335. The database 335 mayreside in a variety of locations. By way of example, database 335 mayreside on a storage medium local to (and/or resident in) one or more ofthe computers 305, 310, or on a storage medium local to one or more ofthe controllers/microprocessor(s) 200 of the devices 10. Alternatively,the database 335 may be remote from any or all of the computers orcontrollers, and in communication (e.g., via the network 320) with oneor all of the computers and controllers. The database 335 may reside ina storage-area network (“SAN”) familiar to those skilled in the art.Similarly, any necessary files for performing the functions attributedto the computers and/or controllers/microprocessors may be stored remotefrom or locally on the respective computers or controllers. The database335 may be a relational database, such as Oracle 10i™, that is adaptedto store, update, and retrieve data in response to SQL-formattedcommands.

As also shown in the FIG. 16, the controllers/microprocessor(s) 200 eachcommunicate with other components of the system 300 through the network320. Although the controllers/microprocessors 200 may have thecapability to independently operate and control their correspondingdevices 10, additional features of the invention may be available whenthe controllers are incorporated within the communication system 300.For example, if a device is moved from one location to another, thecontroller could receive updated algorithms that provide more closelymatched programming features corresponding to the particular environmentin which the devices may operate. Additionally, software or othercommand updates may be downloaded to the controllers/microprocessorsthereby eliminating the need for manual software updates. Additionally,information may be uploaded from the controllers/microprocessors. Thisinformation may be used as historical operating data to improve softwareprogramming or other aspects of control for the devices. Since thedevices may be operating in remote or austere conditions, the capabilityfor the controllers to communicate through a communications network canprovide other benefits. For example, if a controller experiences amalfunction or suffers from a reduced functional capacity, it would bepossible to bypass control of the device as normally provided by thecontroller/microcontroller by commands sent through one or more of theremote computers. In the event there are a multitude of devicesfunctioning simultaneously within one or more locations, the computingcapability of the server 325 may be advantageous in providing additionalor supplemental control to the devices. Additionally, the database 335can be useful in compiling operational data for the devices in order toimprove the sets of algorithms and software commands that may beassociated with operation of the devices. Those skilled in the art canappreciate other advantages of incorporating a device 10 within acommunication system 300.

In accordance with methods of the present invention, a device removeswater vapor from an incoming, ambient airstream. The exhaust airstreamleaving the device is therefore a dried or water lean airstream.Operation of the device can conceptually be divided into two maincycles, namely, a charge cycle and an extraction cycle. In the chargecycle, the ambient airstream is passed through a chamber, across adesiccant stack, and back to the environment. The desiccant absorbswater vapor in the air stream. The desiccant is preferably employed in aliquid solution with water. The desiccant solution is distributed in thechamber by a desiccant media, including a plurality of media sheets,preferably in folded media sheets configured within media cartridgesdisposed in each tray of the desiccant stack.

In accordance with the methods, a charge cycle includes absorption ofwater vapor, and controlling the amount of water vapor removed from theairstream such that the desiccant solution does not become oversaturated with water. In arid climates, it may be advantageous to runthe charge cycle during nighttime hours when the relative humidity risesdue to a corresponding drop in ambient air temperature. A controlledflow of air is passed through the chamber of the device by one or morefans. As set forth above in the illustrated preferred embodiment, one ormore fans may be located at the entrance to the chamber, coupled withone or more fans located at the exit of the chamber. Airflow sensorsalong with temperature and humidity sensors monitor the state of thechamber. An optimum airflow through the chamber is achieved to match thedesired quantity of water to be recovered. If a relatively small amountof water is the recovery requirement, then a smaller volume of air ispassed through the chamber as compared to a larger water recoveryrequirement that must be attained in the same amount of operation time.Once the desiccant media has absorbed the requisite amount of water forthe charge cycle, an extraction cycle is commenced. First, the chamberis isolated from the ambient airstream by closing all valves or dampersthat communicate with the surrounding environment. Heat energy is addedto the chamber. This may be achieved by use of a heat exchanger that hasmany possible sources of power. Heat energy is added to a predeterminedpoint in which vaporization occurs for the water within the chamber. Atthis point, the moist air within the chamber can be circulated through acondenser. Preferably, the condenser does not require a separate sourceof power for cooling. Rather, it is preferred to initiate condensingwhen the internal temperature within the chamber exceeds a dew pointtemperature relative to the external ambient temperature. Accordingly,the cooling “source” for the condenser is simply the ambient air, and aflow of ambient air is passed through the condenser to achievecondensing of the moist chamber air. The condenser has a passageway,typically defined by a cooling coil, in which the cooler temperature ofthe coil causes the water vapor to condense. Water droplets condensed onthe surfaces of the condensing coil are collected in a container thatcommunicates with the condensing coil. During this condensing phase ofthe extraction cycle, heat continues to be added to the chamber for aperiod of time to evaporate a desired amount of water trapped within thechamber. Accordingly, recirculation of the air within the chamber occursin which a return line is provided from the condenser back to thechamber. In addition to adding heat to the chamber, the vaporizationtemperature of the water can be more easily achieved by reducing thepressure within the chamber. For example, a partial vacuum can be drawnfor the air within the chamber, and the remaining amount of air withinthe chamber can be heated and re-circulated during the condensing phase.

Further in accordance with methods of the invention, it is contemplatedthat optimal desiccant solution ratios are maintained for each reservoirof solution within each tray. Liquid level sensors along with chemicalconcentration sensors may be employed in each tray to monitor liquidlevels and desiccant concentrations. As needed, desiccant solution canbe replaced and/or water may be automatically added to each tray assupplied from supply reservoirs that communicate with each of the trays.

Further in accordance with the device and methods of the invention, themajority of the desiccant (both in wet and dry states) is stored in atray while a minority percentage is stored in the PVA foam, resulting inrelatively high water storage capacity. This configuration is incontrast to traditional water recovery systems in which desiccant isconfined to the PVA foam, which does not provide as high of a waterstorage capacity.

Further in accordance with methods of the invention, the desiccant andcartridge design of the disclosed device allows for a simplifiedtwo-stage charge. That is, desiccant is placed into a tray and thedevice is run for a charge cycle. Upon saturation of the desiccant, anequilibrium amount of desiccant is embedded into the PVA foam or otherwick material for subsequent charge cycles. Accordingly, there is noneed for other special treatment steps to prepare the PVA foam to acceptthe desiccant, and there is no need to wet or dry the PVA foam to reachthe equilibrium amount of desiccant in the next upcoming charge cycle.

Further in accordance with methods of the invention, the dried airstreamthat is produced during a charge cycle can be used to condition theinterior airspace of a man-made structure. Accordingly, duct work may beconnected to the exhaust airstream interconnecting the exhaust airstreamwith the interior airspace.

Also in accordance with methods of the invention, the modularconstruction of the device allows for easily changing the water recoverycapacity of the device. Therefore, it is contemplated that waterrecovery capability can be optimized by changing the number of traysused by changing the exposed surface area of the media cartridges,and/or changing the flow path of air through the chamber. As discussed,a serial flow path through the chamber or a parallel flow path throughthe chamber changes the dwell time of the airstream within the chamber.These different flow paths also result in greater or lesser contact ofthe desiccant media with the airstream which, in turn, alters the rateat which water is absorbed by the desiccant. Additionally, the flow rateof air through the chamber of the device can also be adjusted to meetthe desired water recovery requirement. In general, a greater flow rateof air through the chamber should result in a greater amount of waterrecovered as compared to a lesser flow rate.

Also in accordance with methods of the invention, it is contemplatedthat dynamic programming is used with a controller/microprocessor tooptimize device operation. Within the controller/microprocessorprogramming, algorithms can be used that establish base line or initialoperation parameters based upon known environmental factors. Theseenvironmental factors include daily temperature data, daylight data,humidity data, wind data, and potential damage scenario data. Each ofthese factors may ultimately affect the operation of the device. Withrespect to temperature and humidity data, this data will partiallydetermine optimum times for operating the cycles of the device. Thedaylight data also helps to define when temperature and humidity changeswill most rapidly occur during average temperature conditions. Wind datacan be used to ensure the device is oriented in the proper directionsuch that a constant flow of air can be provided through the devicewithout undue affects of adverse wind conditions. Potential damagescenarios relate to the specific location where the device is placed,and the chances that a human or environmental event will damage ordestroy the device. By evaluating each of these factors as compared todifferent geographical locations, initial setup and operation of adevice is simplified and initially optimized. As a particular device isplaced into operation, continued monitoring of environmental conditionsalong with the operational capability of the device can be used to alterthe initial operational algorithms to then establish optimal operationalparameters. Because multiple devices may be employed in austere ordifficult to travel locations, it is also advantageous to incorporatethe devices within a communications network in which operation of thedevices may also be controlled remotely. For example, consider a devicethat has been damaged, or has one or more components that are notfunctioning to capacity. In this scenario, commands may be issued from aremote computing device to change the current operational algorithms tocompensate for the damage to components. One specific example couldrelate to a component such as a fan or valve that has limitedfunctioning, and therefore, the operational algorithm could be modifiedto change the operation of these elements in order to meet the desiredwater recovery goal.

Also in accordance with methods of the present invention, it may bepossible to determine the optimum times for running a charge cyclesimply by evaluating nighttime hours. For example, light sensors and atime of day clock may be used by the controller to initiate andterminate a charge cycle, the conclusion in this method of control beingthat nighttime hours are the best for running the charge cycle.

Further in accordance with methods of the invention, it is contemplatedthat the recovered water may be further treated to ensure it is potable.For example, a number of additional water treatment measures may betaken to make the water potable. Such measures may include filtration,exposure to ultraviolet light, mineralization, chlorination, and/orfurther chemical treatment.

Further in accordance with methods of the invention, it is contemplatedthat in lieu of a single heat exchanger, a desiccant stack may takeadvantage of multiple heat exchanging assemblies powered by a singlesource of power. Accordingly, selected trays within a desiccant stackmay be disposed between one or more heat exchanging assemblies in whicheach assembly has a heating line, a heat distribution element, andsensors. These assemblies may each have their own housing, or the traysmay be modified to incorporate the heat exchanging assemblies in which asingle housing can be used for both a desiccant tray and heat exchangingassembly combination.

While illustrative embodiments have been described in detail herein, itis to be understood that the concepts may be otherwise variouslyembodied and employed, and that the appended claims are intended to beconstrued to include such variations, except as limited by the priorart.

1. A water recovery device comprising: a desiccant stack including achamber defining an airflow path therein, the stack including aplurality of desiccant trays, each tray including a desiccant mediacartridge and a desiccant placed within the tray and being absorbed by amedia material of the media cartridge; a condenser communicating withthe desiccant stack; a heat exchanger communicating with the desiccantstack for providing heat to the desiccant stack; wherein the waterrecovery device is operated in a charge cycle for circulating ambientair through the chamber to remove water vapor by the desiccant andretaining water vapor in the chamber, the device being further operatedin an extraction cycle to remove the retained water vapor within thechamber, the condenser providing a cooling source to condense the watervapor and thereby producing an amount of water condensate.
 2. A waterrecovery device, as claimed in claim 1, further comprising: a controllerincorporated in the device for controlling functioning of the device toinclude the charge cycle and the extraction cycle, the device furtherincluding a plurality of sensors as inputs to the controller, and aplurality of valves and fans as outputs of the controller, the valvesand fans being located within air transport lines of the device. 3-6.(canceled)
 7. A water recovery device, as claimed in claim 1, wherein:the condenser comprises a cooling coil for cooling air received from thechamber and to condense water vapor in the air, the water vapor beingcollected on interior surfaces of the cooling coil, and an ambient aircooling line communicating with the cooling coil, the ambient aircooling line receiving and passing a stream of ambient air through theambient air cooling line to cool the cooling coil, and to thereby causecondensing of the water vapor.
 8. A water recovery device, as claimed inclaim 1, wherein: each desiccant tray includes a plurality of sidewallsand a base, the desiccant being placed in the base, and the mediacartridge being partially submerged within the desiccant.
 9. A waterrecovery device, as claimed in claim 1, wherein the media cartridgeincludes the media material configured in an accordion foldedarrangement and placed within a media frame.
 10. A water recoverydevice, as claimed in claim 9, wherein: the media frame further includesat least one media frame panel and at least one media frame screen, andan internal media wire support for maintaining the media material in itsaccordion folded arrangement.
 11. A water recovery device, as claimed inclaim 1, wherein: the media cartridge includes the media material placedin a configuration having a plurality of folds and a plurality of gapsbetween the folds, the media material being oriented such that anairstream flowing through the chamber flows substantially parallel tothe folds of the media material.
 12. A water recovery device, as claimedin claim 1, wherein: the heat exchanger is placed below the desiccantstack, and an airstream flowing through the device first flows throughthe heat exchanger and then through the chamber. 13-15. (canceled)
 16. Awater recovery device, as claimed in claim 1, wherein: each tray has aplurality of sidewalls and a base containing an amount of the liquiddesiccant therein, at least one of the sidewalls or base having aplurality of air circulating slots formed therein to enable the ambientair to be circulated through the slots.
 17. (canceled)
 18. (canceled)19. The water recovery device of claim 1, wherein the media materialcomprises at least one material selected from the group consisting of asilica gel, activated charcoal, calcium sulfate, calcium chloride,montmorillonite clay, crushed aluminum, alumino silicates, sodiumalumino silicates, ceramic, porous ceramic, cellular plastic, expandedmetal foil, coarse fiber, felt, alumina ball, glass fiber, membrane andmicro-cellulous, metal oxides, metal chlorides, metal silanes, hydrides,calcium silicates, calcium sulfate, magnesium sulfate, calcium chloride,calcium oxide, portland cement, perlite, vermiculite, attapulgite clay,bentonite clay, phosphorous pentoxide, aluminum phosphate, aerogel,glycerin, phosphorous pentoxide, a zeolite, zeolite A, zeolite 13X,silica gel granules coated with cobalt chloride, silica gel pellets, andmolecular sieves.
 20. The water recovery device of claim 1, wherein themedia material comprises at least one liquid desiccant comprising ioniccompounds comprising an anion selected from acetate, fluoride, chloride,thiocyanate, dicyanamide, chlorate, perchlorate, nitrite, nitrate,sulfate, hydrogensulfate, carbonate, hydrogencarbonate, methylcarbonate,phosphate, hydrogenphosphate, dihydrogenphosphate, phosphonate HPO₃ ²⁻,hydrogenphosphonate H₂PO₃ ⁻, sulfamate H₂N—SO₃ ⁻, deprotonatedacesulfame, deprotonated saccharine, cyclamate, tetrafluoro-borate,trifluoromethanesulfonate, methanesulfonate,nonadecafluoro-nonansulfonate and p-toluolsulfonate, methylsulfate,ethylsulfate, n-propylsulfate, i-propylsulfate, butylsulfate,pentylsulfate, hexylsulfate, heptylsulfate, octylsulfate, nonylsulfate,decylsulfate, long-chain n-alkylsulfate, benzylsulfate,trichloroacetate, dichloroacetate, chloroacetate, trifluoroacetate,difluoroacetate, fluoroacetate, methoxyacetate, cyanacetate, glykolate,benzoate, pyruvate, malonate, pivalate, the deprotonated or partiallydeprotonated form of the following monovalent or polyvalent acids:formic acid, acetic acid, propionic acid, butyric acid, valeric acid,caproic acid, enanthic acid, caprylic acid, capric acid, lauric acid,myristic acid, palmitic acid, stearic acid, arachidic acid,O-acetylsalicylic acid, sorbic acid, pivalic acid, fatty acids,isoleucine, alanine, leucine, asparagine, lysine, aspartic acid,methionine, cysteine, phenylalanine, glutamic acid, threonine,glutamine, tryptophan, glycine, valine, proline, serine, tyrosine,arginine, histidine, ornithine, taurine, sulfamic acid, aldonic acids,ulosonic acids, uronic acids, aldaric acids, gluconic acid, glucuronicacid, mannonic acid, mannuronic acid, galactonic acid, galacturonicacid, ascorbic acid, glyceric acid, xylonic acid, neuraminic acid,iduronic acid, oxalic acid, malonic acid, succinic acid, glutaric acid,adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid,phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaricacid, glutaconic acid, traumatic acid, muconic acid, citric acid,isocitric acid, aconitic acid, propane-1,2,3-tricarboxylic acid,trimesic acid, glycolic acid, lactic acid, malic acid, citric acid,tartaric acid, mandelic acid, 2-hydroxybutyric acid, 3-hydroxybutyricacid, 4-hydroxybutyric acid, 3-hydroxypropionic acid,3-hydroxyisoyaleric acid, salicylic acid, polycarboxylic acids, PF₆⁻[PF₃(CF₃)₃]⁻, [PF₃(C₂F₅)₃]⁻, [PF₃(C₃F₇)₃]⁻, [PF₃(C₄F₇)₃]⁻,[F₃C—SO₂—N—SO₂—CF₃]⁻, [F₃C—SO₂—N—CO—CF₃]⁻, [F₃C—CO—N—CO—CF₃]⁻,dimethylphosphate, diethylphosphate, dibutylphosphate, dimethylphosphonate, diethyl phosphonate, dibutyl phosphonate, and mixturesthereof, and a cation selected from tetramethylammonium,tetraethylammonium, tetrabutylammonium tetrahexylammonium,tetraoctylammonium, trimethylammonium, triethylammonium,tributylammonium, triethylmethylammonium, tributylmethylammonium,trihexylmethylammonium, trioctylmethylammonium,tris-(2-Hydroxyethyl)methylammonium, tris-(2-Hydroxyethyl)ethylammonium,bis-(2-hydroxyethyl)dimethylammonium, 1,3-dimethylimidazolium,1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium,1-butyl-3-methylimidazolium, 1,2,3-trimethylimidazolium,1,3-diethylimidazolium, 1,3-dibutylimidazolium,1-ethyl-2,3-dimethylimidazolium, 1-butyl-2,3-dimethylimidazolium,1-(2-hydroxyethyl)-3-methylimidazolium,1-(3-hydroxypropyl)-3-methylimidazolium,1-(2-hydroxypropyl)-3-methylimidazolium,1-(4-hydroxy-butyl)-3-methylimidazolium,1-(3-hydroxy-butyl)-3-methylimidazolium,1-(2-hydroxy-butyl)-3-methylimidazolium,1-(2-methoxyethyl)-3-methylimidazolium,1-(3-methoxypropyl)-3-methylimidazolium,1-(2-methoxypropyl)-3-methylimidazolium,1-(4-methoxy-butyl)-3-methylimidazolium,1-(3-methoxy-butyl)-3-methylimidazolium,1-(2-methoxy-butyl)-3-methylimidazolium,1-(2-ethoxyethyl)-3-methylimidazolium,1-(3-ethoxypropyl)-3-methylimidazolium,1-(2-ethoxypropyl)-3-methylimidazolium,1-(4-ethoxy-butyl)-3-methylimidazolium,1-(3-ethoxy-butyl)-3-methylimidazolium,1-(2-ethoxy-butyl)-3-methylimidazolium, 1-allyl-3-methylimidazolium,1-allyl-2,3-dimethylimidazolium, N,N-dimethylmorpholinium,N,N-diethylmorpholinium, N,N-dibutylmorpholinium,N-ethyl-N-methylmorpholinium, N-butyl-N-methylmorpholinium,N,N-dimethylpiperidinium, N,N-diethylpiperidinium,N,N-dibutylpiperidinium, N-ethyl-N-methylpiperidinium,N-butyl-N-methylpiperidinium, N,N-dimethylpyrrolidinium,N,N-diethylpyrrolidinium, N,N-dibutylpyrrolidinium,N-ethyl-N-methylpyrrolidinium, N-butyl-N-methylpyrrolidinium,2-Hydroxyethyltrimethylammonium (choline),2-acetoxyethyl-trimethylammonium (acetylcholine), guanidinium(protonated guanidine, tetramethylguanidinium, pentamethylguanidinium,hexamethylguanidinium triethylmethylphosphonium,tripropylmethylphosphonium, tributylmethylphosphonium,tetraethylphosphonium, tetrapropylphosphonium, tetrabutylphosphonium,tetramethylphosphonium, and mixtures thereof.
 21. The water recoverydevice of claim 1, wherein the media material is a solid media materialthat has been surface treated to change the surface area of the mediamaterial.
 22. The water recovery device of claim 1, wherein the surfacetreatment is selected from passivation, chlorination, fluoridation,activation, etching, drilling, cutting, abrasion, solvent treatment, theapplication of primer coatings, the application of surfactants, plasmatreatment, ion bombardment/implantation, and covalent bonding.
 23. Awater recovery system comprising: (a) water recovery device including:(1) a desiccant stack including a chamber defining an airflow paththerein, the stack including a plurality of desiccant trays, each trayincluding a desiccant media cartridge and an amount of desiccant placedwithin the tray and being absorbed by a media material of the mediacartridge; (2) a condenser communicating with the desiccant stack; (3) aheat exchanger communicating with the desiccant stack for providing heatto the desiccant stack; wherein the water recovery device is operated ina charge cycle for circulating ambient air through the chamber to removewater vapor by the desiccant and retaining water vapor in the chamber,the device being further operated in an extraction cycle to remove theretained water vapor within the chamber, the condenser providing acooling source to condense the water vapor and thereby producing anamount of water condensate; (b) a controller incorporated in the devicefor controlling functioning of the device to include the charge cycleand the extraction cycle, the device further including a plurality ofsensors as inputs to the controller, and a plurality of valves and fansas outputs of the controller, the valves and fans being located withinair transport lines of the device; (c) said water recovery devicefurther including a communications node incorporated within acommunications system enabling the water recovery device to communicatewithin the communications system. 24-29. (canceled)
 30. The waterrecovery device of claim 23, wherein the media material comprises atleast one liquid desiccant comprising ionic compounds comprising ananion selected from acetate, fluoride, chloride, thiocyanate,dicyanamide, chlorate, perchlorate, nitrite, nitrate, sulfate,hydrogensulfate, carbonate, hydrogencarbonate, methylcarbonate,phosphate, hydrogenphosphate, dihydrogenphosphate, phosphonate HPO₃ ²⁻,hydrogenphosphonate H₂PO₃ ⁻, sulfamate H₂N—SO₃ ⁻, deprotonatedacesulfame, deprotonated saccharine, cyclamate, tetrafluoro-borate,trifluoromethanesulfonate, methanesulfonate,nonadecafluoro-nonansulfonate and p-toluolsulfonate, methylsulfate,ethylsulfate, n-propylsulfate, i-propylsulfate, butylsulfate,pentylsulfate, hexylsulfate, heptylsulfate, octylsulfate, nonylsulfate,decylsulfate, long-chain n-alkylsulfate, benzylsulfate,trichloroacetate, dichloroacetate, chloroacetate, trifluoroacetate,difluoroacetate, fluoroacetate, methoxyacetate, cyanacetate, glykolate,benzoate, pyruvate, malonate, pivalate, the deprotonated or partiallydeprotonated form of the following monovalent or polyvalent acids:formic acid, acetic acid, propionic acid, butyric acid, valeric acid,caproic acid, enanthic acid, caprylic acid, capric acid, lauric acid,myristic acid, palmitic acid, stearic acid, arachidic acid,O-acetylsalicylic acid, sorbic acid, pivalic acid, fatty acids,isoleucine, alanine, leucine, asparagine, lysine, aspartic acid,methionine, cysteine, phenylalanine, glutamic acid, threonine,glutamine, tryptophan, glycine, valine, proline, serine, tyrosine,arginine, histidine, ornithine, taurine, sulfamic acid, aldonic acids,ulosonic acids, uronic acids, aldaric acids, gluconic acid, glucuronicacid, mannonic acid, mannuronic acid, galactonic acid, galacturonicacid, ascorbic acid, glyceric acid, xylonic acid, neuraminic acid,iduronic acid, oxalic acid, malonic acid, succinic acid, glutaric acid,adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid,phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaricacid, glutaconic acid, traumatic acid, muconic acid, citric acid,isocitric acid, aconitic acid, propane-1,2,3-tricarboxylic acid,trimesic acid, glycolic acid, lactic acid, malic acid, citric acid,tartaric acid, mandelic acid, 2-hydroxybutyric acid, 3-hydroxybutyricacid, 4-hydroxybutyric acid, 3-hydroxypropionic acid,3-hydroxyisoyaleric acid, salicylic acid, polycarboxylic acids, PF₆ ⁻,[PF₃(CF₃)₃]⁻, [PF₃(C₂F₅)₃]⁻, [PF₃(C₃F₇)₃]⁻, [PF₃(C₄F₇)₃]⁻,[F₃C—SO₂—N—SO₂—CF₃]⁻, [F₃C—SO₂—N—CO—CF₃]⁻, [F₃C—CO—N—CO—CF₃]⁻,dimethylphosphate, diethylphosphate, dibutylphosphate, dimethylphosphonate, diethyl phosphonate, dibutyl phosphonate, and mixturesthereof, and a cation selected from tetramethylammonium,tetraethylammonium, tetrabutylammonium tetrahexylammonium,tetraoctylammonium, trimethylammonium, triethylammonium,tributylammonium, triethylmethylammonium, tributylmethylammonium,trihexylmethylammonium, trioctylmethylammonium,tris-(2-Hydroxyethyl)methylammonium, tris-(2-Hydroxyethyl)ethylammonium,bis-(2-hydroxyethyl)dimethylammonium, 1,3-dimethylimidazolium,1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium,1-butyl-3-methylimidazolium, 1,2,3-trimethylimidazolium,1,3-diethylimidazolium, 1,3-dibutylimidazolium,1-ethyl-2,3-dimethylimidazolium, 1-butyl-2,3-dimethylimidazolium,1-(2-hydroxyethyl)-3-methylimidazolium,1-(3-hydroxypropyl)-3-methylimidazolium,1-(2-hydroxypropyl)-3-methylimidazolium,1-(4-hydroxy-butyl)-3-methylimidazolium,1-(3-hydroxy-butyl)-3-methylimidazolium,1-(2-hydroxy-butyl)-3-methylimidazolium,1-(2-methoxyethyl)-3-methylimidazolium,1-(3-methoxypropyl)-3-methylimidazolium,1-(2-methoxypropyl)-3-methylimidazolium,1-(4-methoxy-butyl)-3-methylimidazolium,1-(3-methoxy-butyl)-3-methylimidazolium,1-(2-methoxy-butyl)-3-methylimidazolium,1-(2-ethoxyethyl)-3-methylimidazolium,1-(3-ethoxypropyl)-3-methylimidazolium,1-(2-ethoxypropyl)-3-methylimidazolium,1-(4-ethoxy-butyl)-3-methylimidazolium,1-(3-ethoxy-butyl)-3-methylimidazolium,1-(2-ethoxy-butyl)-3-methylimidazolium, 1-allyl-3-methylimidazolium,1-allyl-2,3-dimethylimidazolium, N,N-dimethylmorpholinium,N,N-diethylmorpholinium, N,N-dibutylmorpholinium,N-ethyl-N-methylmorpholinium, N-butyl-N-methylmorpholinium,N,N-dimethylpiperidinium, N,N-diethylpiperidinium,N,N-dibutylpiperidinium, N-ethyl-N-methylpiperidinium,N-butyl-N-methylpiperidinium, N,N-dimethylpyrrolidinium,N,N-diethylpyrrolidinium, N,N-dibutylpyrrolidinium,N-ethyl-N-methylpyrrolidinium, N-butyl-N-methylpyrrolidinium,2-Hydroxyethyltrimethylammonium (choline),2-acetoxyethyl-trimethylammonium (acetylcholine), guanidinium(protonated guanidine, tetramethylguanidinium, pentamethylguanidinium,hexamethylguanidinium triethylmethylphosphonium,tripropylmethylphosphonium, tributylmethylphosphonium,tetraethylphosphonium, tetrapropylphosphonium, tetrabutylphosphonium,tetramethylphosphonium, and mixtures thereof. 31-32. (canceled)
 33. Amethod of recovering water from an ambient airstream comprising: (a)directing an ambient airstream to a water recovery device comprising:(1) a desiccant stack including a chamber defining an airflow paththerein, the stack including a plurality of desiccant trays, each trayincluding a desiccant media cartridge and an amount of liquid desiccantplaced within the tray and being absorbed by a media material of themedia cartridge; (2) a condenser communicating with the desiccant stack;(3) a heat exchanger communicating with the desiccant stack forproviding heat to the desiccant stack; wherein the water recovery deviceis operated in a charge cycle for circulating ambient air through thechamber to remove water vapor by the liquid desiccant and retainingwater vapor in the chamber, the device being further operated in anextraction cycle to remove the retained water vapor within the chamber,the condenser providing a cooling source to condense the water vapor andthereby producing an amount of water condensate; and, (b) collecting thewater condensate.
 34. (canceled)
 35. The method of recovering water, asclaimed in claim 33, wherein: the media material comprises at least oneliquid desiccant comprising ionic compounds comprising an anion selectedfrom acetate, fluoride, chloride, thiocyanate, dicyanamide, chlorate,perchlorate, nitrite, nitrate, sulfate, hydrogensulfate, carbonate,hydrogencarbonate, methylcarbonate, phosphate, hydrogenphosphate,dihydrogenphosphate, phosphonate HPO₃ ²⁻, hydrogenphosphonate H₂PO₃ ⁻,sulfamate H₂N—SO₃ ⁻, deprotonated acesulfame, deprotonated saccharine,cyclamate, tetrafluoro-borate, trifluoromethanesulfonate,methanesulfonate, nonadecafluoro-nonansulfonate and p-toluolsulfonate,methylsulfate, ethylsulfate, n-propylsulfate, i-propylsulfate,butylsulfate, pentylsulfate, hexylsulfate, heptylsulfate, octylsulfate,nonylsulfate, decylsulfate, long-chain n-alkylsulfate, benzylsulfate,trichloroacetate, dichloroacetate, chloroacetate, trifluoroacetate,difluoroacetate, fluoroacetate, methoxyacetate, cyanacetate, glykolate,benzoate, pyruvate, malonate, pivalate, the deprotonated or partiallydeprotonated form of the following monovalent or polyvalent acids:formic acid, acetic acid, propionic acid, butyric acid, valeric acid,caproic acid, enanthic acid, caprylic acid, capric acid, lauric acid,myristic acid, palmitic acid, stearic acid, arachidic acid,O-acetylsalicylic acid, sorbic acid, pivalic acid, fatty acids,isoleucine, alanine, leucine, asparagine, lysine, aspartic acid,methionine, cysteine, phenylalanine, glutamic acid, threonine,glutamine, tryptophan, glycine, valine, proline, serine, tyrosine,arginine, histidine, ornithine, taurine, sulfamic acid, aldonic acids,ulosonic acids, uronic acids, aldaric acids, gluconic acid, glucuronicacid, mannonic acid, mannuronic acid, galactonic acid, galacturonicacid, ascorbic acid, glyceric acid, xylonic acid, neuraminic acid,iduronic acid, oxalic acid, malonic acid, succinic acid, glutaric acid,adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid,phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaricacid, glutaconic acid, traumatic acid, muconic acid, citric acid,isocitric acid, aconitic acid, propane-1,2,3-tricarboxylic acid,trimesic acid, glycolic acid, lactic acid, malic acid, citric acid,tartaric acid, mandelic acid, 2-hydroxybutyric acid, 3-hydroxybutyricacid, 4-hydroxybutyric acid, 3-hydroxypropionic acid,3-hydroxyisoyaleric acid, salicylic acid, polycarboxylic acids, PF₆ ⁻,[PF₃(CF₃)₃]⁻, [PF₃(C₂F₅)₃]⁻, [PF₃(C₃F₇)₃]⁻, [PF₃(C₄F₇)₃]⁻,[F₃C—SO₂—N—SO₂—CF₃]⁻, [F₃C—SO₂—N—CO—CF₃]⁻, [F₃C—CO—N—CO—CF₃]⁻,dimethylphosphate, diethylphosphate, dibutylphosphate, dimethylphosphonate, diethyl phosphonate, dibutyl phosphonate, and mixturesthereof, and a cation selected from tetramethylammonium,tetraethylammonium, tetrabutylammonium tetrahexylammonium,tetraoctylammonium, trimethylammonium, triethylammonium,tributylammonium, triethylmethylammonium, tributylmethylammonium,trihexylmethylammonium, trioctylmethylammonium,tris-(2-Hydroxyethyl)methylammonium, tris-(2-Hydroxyethyl)ethylammonium,bis-(2-hydroxyethyl)dimethylammonium, 1,3-dimethylimidazolium,1-ethyl-3-methylimidazolium, 1-propyl-3-methylimidazolium,1-butyl-3-methylimidazolium, 1,2,3-trimethylimidazolium,1,3-diethylimidazolium, 1,3-dibutylimidazolium,1-ethyl-2,3-dimethylimidazolium, 1-butyl-2,3-dimethylimidazolium,1-(2-hydroxyethyl)-3-methylimidazolium,1-(3-hydroxypropyl)-3-methylimidazolium,1-(2-hydroxypropyl)-3-methylimidazolium,1-(4-hydroxy-butyl)-3-methylimidazolium,1-(3-hydroxy-butyl)-3-methylimidazolium,1-(2-hydroxy-butyl)-3-methylimidazolium,1-(2-methoxyethyl)-3-methylimidazolium,1-(3-methoxypropyl)-3-methylimidazolium,1-(2-methoxypropyl)-3-methylimidazolium,1-(4-methoxy-butyl)-3-methylimidazolium,1-(3-methoxy-butyl)-3-methylimidazolium,1-(2-methoxy-butyl)-3-methylimidazolium,1-(2-ethoxyethyl)-3-methylimidazolium,1-(3-ethoxypropyl)-3-methylimidazolium,1-(2-ethoxypropyl)-3-methylimidazolium,1-(4-ethoxy-butyl)-3-methylimidazolium,1-(3-ethoxy-butyl)-3-methylimidazolium,1-(2-ethoxy-butyl)-3-methylimidazolium, 1-allyl-3-methylimidazolium,1-allyl-2,3-dimethylimidazolium, N,N-dimethylmorpholinium,N,N-diethylmorpholinium, N,N-dibutylmorpholinium,N-ethyl-N-methylmorpholinium, N-butyl-N-methylmorpholinium,N,N-dimethylpiperidinium, N,N-diethylpiperidinium,N,N-dibutylpiperidinium, N-ethyl-N-methylpiperidinium,N-butyl-N-methylpiperidinium, N,N-dimethylpyrrolidinium,N,N-diethylpyrrolidinium, N,N-dibutylpyrrolidinium,N-ethyl-N-methylpyrrolidinium, N-butyl-N-methylpyrrolidinium,2-Hydroxyethyltrimethylammonium (choline),2-acetoxyethyl-trimethylammonium (acetylcholine), guanidinium(protonated guanidine, tetramethylguanidinium, pentamethylguanidinium,hexamethylguanidinium triethylmethylphosphonium,tripropylmethylphosphonium, tributylmethylphosphonium,tetraethylphosphonium, tetrapropylphosphonium, tetrabutylphosphonium,tetramethylphosphonium, and mixtures thereof.
 36. (canceled) 37.(canceled)